James Bridges

Glenn Research Center, Cleveland, Ohio

Measurements of Turbulent Flow Field

in Separate Flow Nozzles With Enhanced

Mixing Devices—Test Report

NASA/TM—2002-211366

February 2002
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James Bridges

Glenn Research Center, Cleveland, Ohio

Measurements of Turbulent Flow Field

in Separate Flow Nozzles With Enhanced

Mixing Devices—Test Report

NASA/TM—2002-211366

February 2002

National Aeronautics and

Space Administration

Glenn Research Center
Acknowledgments

The PIV instrumentation used in this work was developed by Dr. Mark P. Wernet of NASA Glenn

Research Center’s Instrumentation Branch. Dr. Wernet also processed the PIV images to velocity maps.

The jet noise suppression nozzles used were designed by engineers at General Electric Aircraft Engines and

at Pratt & Whitney. The jet rig was assembled and operated in the AeroAcoustic Propulsion Laboratory

under the guidance of Mr. Thomas Griffin of the Aeropropulsion Test Engineering Branch.

Available from

NASA Center for Aerospace Information

7121 Standard Drive

Hanover, MD 21076

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22100

This report is a formal draft or working

paper, intended to solicit comments and

ideas from a technical peer group.

Trade names or manufacturers’ names are used in this report for

identification only. This usage does not constitute an official

endorsement, either expressed or implied, by the National

Aeronautics and Space Administration.

This report contains preliminary

findings, subject to revision as

analysis proceeds.

Available electronically at http://gltrs.grc.nasa.gov/GLTRS
Measurements of Turbulent Flow Field in Separate Flow Nozzles with Enhanced 

Mixing Devices—Test Report 

James Bridges 

National Aeronautics and Space Administration 

Glenn Research Center 

Cleveland, Ohio 44135 

1 Abstract 

As part of the Advanced Subsonic Technology Program, a series of experiments was conducted at NASA Glenn 

Research Center on the effect of mixing enhancement devices on the aeroacoustic performance of separate flow 

nozzles. Initial acoustic evaluations of the devices showed that they reduced jet noise significantly, while creating 

very little thrust loss. The explanation for the improvement required that turbulence measurements, namely single 

point mean and RMS statistics and two-point spatial correlations, be made to determine the change in the turbulence 

caused by the mixing enhancement devices that lead to the noise reduction. These measurements were made in the 

summer of 2000 in a test program called Separate Nozzle Flow Test 2000 (SFNT2K) supported by the 

Aeropropulsion Research Program at NASA Glenn Research Center. 

Given the hot high-speed flows representative of a contemporary bypass ratio 5 turbofan engine, unsteady flow field 

measurements required the use of an optical measurement method. To achieve the spatial correlations, the Particle 

Image Velocimetry technique was employed, acquiring high-density velocity maps of the flows from which the 

required statistics could be derived. This was the first successful use of this technique for such flows, and shows the 

utility of this technique for future experimental programs. The extensive statistics obtained were likewise unique and 

give great insight into the turbulence which produces noise and how the turbulence can be modified to reduce jet 

noise. 

This report documents the test facilities and procedures used to obtain the turbulence data. It also contains an 

indexed overview of the results, both in graphical and numerical formats. 

NASA/TM—2002-211366 1
2 Table of Contents 

1 Abstract................................................................................................................................................1 

2 Table of Contents.................................................................................................................................2 

3 Introduction .........................................................................................................................................3 

4 Facilities................................................................................................................................................3 

4.1 AAPL...........................................................................................................................................3 

4.2 NATR ..........................................................................................................................................3 

4.3 JER...............................................................................................................................................4 

4.4 Flow Seeding ...............................................................................................................................6 

5 Models & flow conditions .................................................................................................................10 

5.1 Test plan.....................................................................................................................................11 

5.2 Models tested .............................................................................................................................13 

6 PIV Instrumentation .........................................................................................................................15 

6.2 Laser, cameras, frame grabber...................................................................................................17 

6.3 Acquisition parameters..............................................................................................................18 

7 PIV Analysis.......................................................................................................................................18 

7.1 Image Processing .......................................................................................................................18 

7.2 Definition of turbulence statistics..............................................................................................19 

7.3 Analysis of error ........................................................................................................................22 

8 Presentation of data...........................................................................................................................25 

8.1 Organization of figures..............................................................................................................25 

8.2 Data format of digital data .........................................................................................................25 

9 Summary of Results ..........................................................................................................................26 

9.1 Comparisons with Plume Survey Measurements.......................................................................26 

9.2 Comparisons with Computational Results.................................................................................27 

10 Summary .......................................................................................................................................28 

12 Appendix A: Test narrative..........................................................................................................30 

13 Appendix B: Data plots................................................................................................................36

14 Appendix C: Data files................................................................................................................199

11 References .....................................................................................................................................29

NASA/TM—2002-211366 2
3 Introduction 

NASA’s recent Advanced Subsonic Technology (AST) program had as its goal the reduction of aircraft noise in the 

current and near-term fleet. Hence, it focussed on technologies that were compatible with current engine 

configurations. One of these engine configurations deemed vulnerable to jet noise reduction was the separate flow 

exhaust nozzle. It was believed that nozzle modifications that decreased the core flow velocity in the plume by 

enhancing mixing would cause overall noise reduction. Such modifications would be required to have minimal 

thrust loss to be acceptable as a noise reduction technique. 

In 1997, a series of separate flow nozzle concepts were tested, concepts which were submitted by General Electric 

Aircraft Engines, Pratt & Whitney, Rolls-Royce Allison, and NASA Glenn Research Center. This test was dubbed 

the Separate Flow Nozzle Test 1997 (SFNT97). Several of these nozzle concepts provided significant noise 

reduction benefits with negligible thrust penalty. During the SFNT97, many measurements were made on the jet 

flows: far-field acoustics, total and static pressure and total temperature surveys of the plume, infrared imagery of 

the plume, acoustic source distribution estimation by phased arrays, and Schlieren images. These combined to 

describe the mean flow field and acoustic fields for the jet flows, leading to some understanding of how changes in 

the flow field caused beneficial changes in the acoustic sources. Results of this test are documented in references 1, 

2, 3, and 4. 

As successful as the SFNT97 was, one key class of information was not acquired: unsteady fluid dynamics 

measurements. Turbulence statistics are the main information that aeroacoustic theory requires to relate flow to 

sound. Specifically, leading theories require two-point space-time correlations of the velocity field as input to 

predict acoustic output of the jet flow. Although such measurements were attempted at NASA Langley in 1997, 

researchers were ultimately unsuccessful in obtaining this information. So important were these measurements that a 

second series of tests were performed in 2000 on the original AAPL test rig in a test called SFNT2K, and this time 

the efforts were successful. The datasets for the separate flow nozzle tests now have turbulence measurements, 

including two-point space correlations, for the three most important nozzle configurations. 

Beyond the immediate need for understanding of the results of a particular test is the more general need to explore 

and capture the relationship between turbulence and aeroacoustic noise. Given the difficulty in measuring turbulence 

in hot, high-speed jets, this work was ground-breaking in that it demonstrated the potential of Particle Image 

Velocimetry (PIV) in making the high-order turbulence measurements that are apparently required to establish this 

relationship. This report documents these initial experiments using PIV at the NASA Glenn AeroAcoustic 

Propulsion Laboratory. 

4 Facilities 

The AST Separate Flow Nozzle Tests were conducted at the AeroAcoustic Propulsion Laboratory (AAPL) at NASA 

Glenn Research Center in Cleveland, Ohio. The exhaust nozzle models were mounted on a hydrogen fired jet engine 

exhaust simulator rig inside a freejet, providing a scaled model of engine nozzles at appropriate hot flow conditions 

in simulated flight. These facilities are described below. 

4.1 AAPL 

The Aeroacoustic Propulsion Laboratory (AAPL) at NASA Glenn Research Center is a 65ft (20m) radius, anechoic, 

geodesic-dome. The walls of the dome and approximately half of the floor area are treated with acoustic wedges 

made from fiberglass wool to render the facility anechoic above 220 Hz. A 60 inch (1.5m) exhaust fan in the top of 

the dome provides air circulation. Flows from all rigs are directed out the 55ft (16.8m) wide by 35 ft (10.7) high 

doorway onto an open field bordering on the 9x15 Low Speed Wind Tunnel. 

4.2 NATR 

Within the confines of the AAPL dome is the Nozzle Acoustic Test Rig (NATR), a free-jet, forward-flightsimulation test rig, shown in Figure 4.1. The NATR consists of a 10 ft (3m) diameter acoustically lined duct 

functioning as an ejector for an annular air injector system. The ejector system provides a free-jet Mach number up 

number up to 0.3 at 300 lbm/s (135kg/s), approximately 100lbm/s (19.5kg/s) of which is supplied 

NASA/TM—2002-211366 3
Figure 4.1 NATR positioned in AAPL 

through the ejector driver nozzles by the Laboratory's central air supply system at 150psia (1.0MPa). The remaining 

200 lbm/s (39kg/s) is pulled into the duct through louvered walls in an inlet tunnel. Thirty foot (9m) into the AAPL 

dome the 10 foot (3m) duct contracts to an inner diameter of 53 inches (1.35m); the contraction is an ASME longradius, low-β-ratio nozzle. The 53 inch diameter duct extends for 11.1 feet (3.4m) with a centerline 10 ft (3m) above 

the concrete floor. By careful design of acoustic lining and flow conditioning screens in the tunnel the background 

sound inside the dome facility is extremely low and the freestream turbulence is less than 1 percent [5]. A 16 ft (5m) 

high wall, constructed of aluminum box beam covered with plywood and fiberglass wedges, separates the anechoic 

test area with NATR from the acoustically untreated part of the dome. 

4.3 JER 

The last 12 ft (3.7m) of the NATR is a constant diameter, unlined, duct. Nozzle models to be tested are installed on 

the aft end of the hydrogen-fired jet exit rig (JER) that is located in this duct. The JER is the structure through which 

hot airflow is delivered to the test article via connections to facility compressed air supplies. A detailed description 

of the JER (along with more information about the NATR) is given in Castner[6]. For this program, the JER became 

a tandem-strut arrangement (NASA drawing 28529M42AOOO) consisting of the hydrogen fueled dual stream rig 

(JER) augmented by a dual flow 'pod' attached just aft of the combustor. Only the core stream of the dual stream rig 

was used to provide the hot core flow while the fan flow came from a secondary strut into the dual flow pod. This 

rig setup and arrangement relative to the NATR are shown in Figure 4.2. Locations on the rig are given in inches as 

JER stations relative to the leading point of the rig. 

NASA/TM—2002-211366 4
Figure 4.2 Hydrogen fueled jet exit rig (JER) with Dual Flow Pod in NATR. 

Figure 4.3 Supply piping to jet exit rig and NATR in AAPL. 

Figure 4.3 illustrates the supply piping routing for the 450psig (3.1MPa) and 150 psig (1.0MPa) lines which feed the 

model and the freejet. Supply air at 450psi (3.1MPa) is preheated to roughly fan flow temperature of 600°R (330°K) 

by a natural gas fired heat exchanger outside the dome. The flow is split into core and fan flows, which are 

independently metered and throttled down by a control valve in 4 inch (10cm) flow lines. 

The core air is brought to the base of the JER strut where it is split into 10 flow tubes to pass through the main strut 

of the JER and into the plenum at the upstream end of the rig. For this test, only the five flow tubes connected to the 

primary stream pipe were used. The air is passed through the hydrogen injector plate where the combustion of the 

hydrogen increases its temperature to that of the core flow of an aircraft engine. After passing over flow mixing 

devices to hasten the temperature uniformity, the flow is passed through two choke plates, reticulated metal foam 

and screens. The reticulated foam metal was removed during this test as seed would clog and break the foam metal. 

A charging station constisting of three azimuthally distributed rakes of alternating total pressure and total 

NASA/TM—2002-211366 5
temperature sensors is located just upstream of the beginning of the centerbody section, which is held in the middle 

of the core stream by three thin airfoil struts. The centerbody section holds the nozzle plug. 

The fan air is split into two 3inch (7.6cm) tubes in a manifold by which it is guided through a 16inch (41cm) airfoil 

section that penetrates the NATR in the last 18inches (46cm) of the freejet. The air in the two tubes is rejoined in an 

annular plenum before passing through a series of choke plates, reticulated foam metal and screens. For the PIV 

measurements, a small-hole choke plate replaced the reticulated foam metal to keep seed from clogging and 

destroying the foam metal. In addition, problems developed with the screen downstream of the choke plate and it 

had to be removed. This modification was checked for impact on freestream turbulence levels and found to be 

minimal. A charging station consisting of total pressure and total temperature rakes measures the flow conditions 

immediately before the upstream end of the fan nozzle. 

The JER main bore has axial locations given as stations in inches from the highlight of the upstream tip of the rig. 

Separate-flow exhaust system model fan nozzle hardware was designed to attach to the dual flow pod at cold JER 

station 146.12. Model core cowl/nozzle hardware was designed to attach to the facility core duct at cold JER station 

146.12. Model centerbody/plug hardware was designed to attach to the facility core/tailcone extension weldment at 

cold JER station 142.19. When assembled and positioned, the separate-flow exhaust system fan nozzle exit plane 

was positioned at cold JER station 156.49, and the NATR exit plane was to be located at cold JER station 132.10, 

putting the fan nozzle exit 24inches (51cm) downstream of the freejet exit. The nozzle model centerline was 

elevated about 10 feet (3.05m) above the facility floor. 

Nozzle airflows, pressures, and temperatures are monitored using JER/NATR instrumentation. Mass flow was 

measured using choked-flow venturi located in the 4inch (10cm) supply lines downstream of the fan/core flow split, 

in the long horizontal pipe runs alongside NATR. Two total pressure and two temperature rakes (with five elements 

each) were installed at the charging station of the fan and of the core ducts of the dual flow pod. The fan rakes are 

installed at circumferential angle positions of 0°, 90°, 180°, and 270° (aft looking forward). Core nozzle rakes are 

located at circumferential angles of 60°, 150°, 240°, and 330° (aft looking forward). The PT/TT measurement plane 

for the fan flow is JER station 140.025. The PT/TT measurement plane for the core flow is JER station 140.741. 

4.4 Flow Seeding 

For PIV, the flow motion being measured is marked by use of particles. These particles must be very small so they 

will have no slip relative to the fluid and so that the motion is the same as the fluid motion. This is an ideal case, but 

the smaller the particle, the greater the fidelity. As the particle size increases, high velocity gradients, associated 

with high frequency or small scale motions, are not recorded properly, effectively adding a lowpass filter to the 

measurements. In addition, all fluid must be laden with particles at a density high enough that sufficient particles (5-

10) are found in an interrogation region of the PIV image. This is made difficult when one has several flow streams 

that are mixing together in the measurement region. In these tests three fluids are mixed, the core stream, the fan 

stream, and the ambient. It is also crucial that the seed be fully mixed with its flow long before the measurement 

region, something that can be tricky in high speed rigs. Finally, the seed must not be affected by the high 

temperatures of the gas; this is especially true of the seed in the core stream at 1500°R (833°K). 

In these tests, the core and bypass streams were seeded with aluminum oxide (Al2O3) powder using two identical, 

specially built seeders. The specific gravity of the alumina powder is 3.96 and the particle size distribution has a 

mean of 2.75x10-5 inch (0.7 μm) and a standard deviation of 7.8x10-6 inch (0.2 μm). Alumina is listed on its Material 

Safety Data Sheet (MSDS) as a desiccant with a low health risk by inhalation; it should be treated as a nuisance 

dust. It is non-flammable. The ambient flow was seeded with oil droplets of roughly 0.2-0.3 micron diameter 

produced by a commercial fogger. The manufacturers’ proprietary formulation of fogger oil (a variant of mineral 

oil) has been certified to be non-toxic by the FDA and OSHA. 

4.4.1 Core & Bypass Seed Injection 

4.4.1.1 System description 

The core and fan flows were seeded with aluminum oxide powder, a dry particulate with roughly the consistency of 

corn starch. This material was introduced into the feedstreams well upstream of the rig. Air was tapped from the 

450psia supply line upstream of the control valves through a 1inch (2.5cm) tube, split into core and fan flow streams 

to feed the two seeders for the two streams. This air was brought through remote control valves, regulators, filters, 

and one-way valves and into the seeders. Figure 4.4 is a picture of the seeder carts and regulator/valve equipment 

used to inject the seed into the rig. 

NASA/TM—2002-211366 6
The heavily seeded air destined to be mixed with the fan flow was directed into the fan flow line through a 1 inch 

(2.5cm) flexible hose. A 1inch (2.5cm) boss welded onto the manifold simply dumped this seeded air into the 

feedpipe, giving it 20 diameters or more to mix before the flow dumped into the plenum of the dual flow pod, passed 

through a choke plate and exited the fan nozzle. 

Figure 4.4 Seeder system layout. Circle A denotes the regulator/valve strings, B is the bypass seeder 

cart, C is the core seeder cart, and D is the injection boss for the core flow seed into the core flow piping. 

On the core flow side, hoses from the seeder injected the seed into the 4inch (10cm) feedpipe through a 1 inch 

(2.5cm) boss welded onto the pipe roughly at the bellmouth of the NATR. The seed mixed thoroughly with the main 

core flow over the 50 pipe diameters, through the JER strut, plenum, and combustor before exiting the core nozzle. 

4.4.1.2 Dry seeder design 

The fluidized bed seeder system is comprised of two chambers, a fluidized-bed chamber and a swirl chamber (see 

Figure 4.5). The fluidized bed chamber has a felt metal plate near its bottom which holds the seed material and 

allows air to flow through it, levitating the seed. Air is introduced into this chamber from the bottom. The seed is 

levitated and carried off with the air through a 1 inch (2.5cm) port in the chamber side. This seeded air is brought 

into the swirl chamber below a pair of small tangential jets that set up a swirling flow in the chamber. This swirl 

causes larger particles, or more likely aggregates of particles, to be thrown to the side of the chamber where they 

will drop to the bottom of the chamber. The small particles and air are carried up through a port in the top of the 

chamber and are piped into the supply pipe of the jet rig with a 1 inch (2.5cm) rubber hose. Figure 4.6 is a picture of 

the seeder cart. 

NASA/TM—2002-211366 7
Figure 4.5. Schematic of fluidized bed seeder design.

Figure 4.6. Seeder cart.

Felt Metal

1" plug

(load seed)

90" elbows give

swirl

DRY shop air

1" plug

(cleanout)

Seeded air to model (1"tube)

4" Sch40 SS Pipe

Regulator/Gauge

Solenoid valve

water/oil

trap

120VAC

Pos=open

main 

manual

valve

Fluidized Bed Seeder—jb99

Regulator/Gauge

NASA/TM—2002-211366 8
4.4.1.3 Operation, estimate of seed density

Inlet pressure to the seeders was controlled remotely to appropriately match the back pressure of the rig, as

judged by the seed density obtained in the PIV images. A remote control video camera aimed at the gauges

in the regulator-control valve string monitored the pressures of the seeders. For the setpoint used in this

test, the core flow required roughly 120psia (830kPa) and the fan flow required 160psia (1.1MPa) supply

pressure. The one-way valve kept seed from being blown backwards through the supply string before the

seeder main valve was opened.

Judging by the images, seeding density was very good most of the time. The seeders were not entirely

steady, occasionally puffing a large slug of seed. No doubt deposits of seed within the rig helped to smooth

out the unevenness in the seeder operation. This became apparent by the large amount of seed that was

observed to come from the rig at startup before the seeders were turned on. Changes in internal flow

separations must have loosened deposits of seed within the piping and rig during these changes in flow.

Monitoring the rate at which seed was used, it is estimated that the seeders provided roughly 0.5liters/hour

each, seeding the flow at a rate of 20 particles/mm. Given the light sheet thickness of 0.2mm, this produces

on the order of 10 particles in a 2mm by 2mm interrogation region.

The core and fan stream seeders were usually left running during the run once PIV image acquisition had

begun, even during traverse movement and image storage periods.

4.4.2 Freejet fogger

4.4.2.1 System description

If ambient air around the jet is not seeded, the measured velocity statistics will be biased because the low

speed ambient fluid, entrained by the seeded jet fluid, will not be recorded. Ideally, the jet fluid and

ambient fluid will be seeded at equal density. Having a freejet flow surrounding the model jet is actually an

aid in doing this as the surrounding fluid can be seeded evenly by introducing seed sufficiently far upstream

that it can be thoroughly mixed before the measurement region.

4.4.2.2 Fogger design

In the current test the freejet flow was seeded with oil droplets generated by a light oil fog generator

manufactured by Corona Technologies, Ltd of Canada, specifically model Vicount 5000. This seeder

produces droplets in the 0.2-0.3 micron diameter range at a rate of 5 liters/hour. The seeder functions by

forcing the oil through a heated nozzle along with nitrogen, evaporating the oil in the heated nozzle and

condensing it into the small droplets which quickly form spheres that are essentially ‘dry’, leaving a

minimal oil film on surfaces.

4.4.2.3 Operation in NATR, estimate of seed density

The fogger was placed in the NATR inlet house, four feet upstream of the NATR freejet ejector plane on

the centerline of the NATR. The fogger was supplied by facility nitrogen, regulated to 60 psig (410kPa).

The remote control feature of the fogger was replaced by a directly wired switch line to the laser trailer

control panel because the metal enclosure of the inlet house shielded the radio frequency remote control.

The fogger was activated shortly before data acquisition was to commence, and was typically left on during

the entire 45 minute run period.

It is important to note that although the droplets were 0.2 – 0.3 micron in diameter, the image formed on the

imaging plane of the camera was larger, being the diffraction limited size produced by the long focal length

lens. This is satisfactory, providing the fluid marker functionality while having less mass and hence higher

frequency response.

Based upon PIV images and on estimates of delivery rates of the fogger and the freejet mass flow at

M=0.28 (300 lbm/s or 135kg/s), the particle density was estimated to be 1000 particles/mm3

 in the

measurement region near the nozzle exit. Given the light sheet thickness of 0.2mm, this produces on the

order of 100 particles in a 2mm by 2mm interrogation region.

NASA/TM—2002-211366 9
Figure 4.7 is a typical image taken at the core nozzle exit illustrating seeding density. Note the relative

uniformity of the seed in the core and fan streams; this was not always the case, but did not seem to

adversely affect the data within the range of variation we observed. Also note the discernable difference

between the fan and ambient seeding, manifest of the difference in seed size and density.

Figure 4.7. Example of PIV image showing seed density.

4.4.2.4 Prelim tests, lessons learned

Some ad hoc trials on placement of the fogger in the inlet area were run using a laser sheet normal to the jet

axis to determine the fog effectiveness at the downstream end of NATR. Although the data was acquired on

a vertical plane below the model, placing the fogger two feet below centerline at the inlet did not improve

seed density significantly in the measurement region and risked missing some fluid entrained from above

the jet. In the end it was found that putting the fogger on the centerline of the NATR gave adequate seed

density for all regions of the jet being measured, roughly 12 inches (30cm) below centerline and up to 120

inches (3m) downstream of the NATR exit.

Although one Vicount 5000 fogger usually seemed sufficient, a second fogger was added just below the

first when it appeared that the first fogger was not as effective as needed. Eventually it was found that the

nitrogen pressure was insufficient on the original fogger and the second fogger was no longer used after

this was corrected. It was also found to be necessary to clean the fogger nozzle occasionally by reaming it

with the manufacturer-provided drill bit.

Placing the fogger only four feet upstream of the centerbody of the NATR ejector resulted in the

centerbody becoming coated with oil. Before it was discovered that the fogger nozzle required periodic

cleaning, large oil droplets were observed in a few of the PIV images. This was due to sputtering of the

fogger, collecting oil on the NATR that then shed off in large drops. When the test was finished, the NATR

screens were cleaned of oil and other debris; it is not clear how much of this oil loading occurred while the

fogger was operating properly and how much occurred during the time the fogger was sputtering.

5 Models & flow conditions

This chapter describes the three models that were extensively studied, and gives full description of the

nozzle geometries and flow conditions measured. It also includes a quick test narrative that indicates some

of the difficulties experienced during the test.

NASA/TM—2002-211366 10
5.1 Test plan

5.1.1 Models tested

In the PIV portion of the SFNT2K covered in this report, three nozzles were measured in detail. These were

the baseline (3BB), alternating 12 count chevron (3A12B), and 24 count alternating tabbed nozzle (3T24B).

These were chosen because they had the most dramatic (and beneficial!) acoustic and mean flow changes

as measured during the 1997 SFNT. The SFNT series models were named by a convention comprised of a

number followed by two letters. The number signified bypass ratio and whether the model had an internal

or external plug. The two single-letter designations denoting the type of mixing enhancement device on the

core and on the fan, the first letter referring to the core nozzle and the second to the fan nozzle. Subscripts

on the letters gave the count of the tabs or chevrons on each nozzle. For this test all models were of the 3xx

series, being of bypass ratio 5 and having an external plug.

5.1.2 Simulated Engine Power Conditions

For the PIV test only one flow condition was used, that being the power code 21 as defined in the SFNT97

test plan. This condition is a simulation of a take-off power setting of a contemporary subsonic medium to

large commercial transport craft and is given in the table below. The facility controllers were set to

maintain 0.5% tolerance of all four parameters.

The freejet was run at M=0.28, again to simulate flight effects during takeoff. This value was maintained

during the runs to within 1.5%.

Table 5.1. Flow conditions tested.

Stream NPR Ttotal (°R)

Fan 1.830 600

Core 1.680 1500

5.1.3 Data acquired

In the test results being reported herein, a two-component PIV system employing two cameras was used to

measure axial and radial velocity components in a single plane. The two cameras were used in tandem, one

above the other, with slightly overlapping fields of view to decrease test time. The field of view was

traversed axially to cover the first 95 inches (2.4m) of the jet flow field with 400 image pairs being

collected from each camera at each location. From these images instantaneous velocity maps were created,

and standard single-point and two-point turbulent velocity statistics were computed.

In a follow-on test that has not yet been fully analyzed, three-component stereo images were acquired for

the same nozzles; however, due to problems with vibration of camera mounts it is doubtful that any but a

handful of this data will be satisfactory.

5.1.4 Spatial regions measured

The test plan for the PIV portion of SFNT2K was to thoroughly measure as much of the jet plume as

possible within the axial limitations of the traverse, assuming symmetry. For the baseline 3BB nozzle this

required only one radial plane. Because 3A12B and 3T24B models had a 30° symmetry, this entailed

acquiring seven planes of data. By virtue of the adaptor spool piece just upstream of the final core nozzle

having 9 holes on its upstream flange and 8 on its downstream, a 5 degree angular increment in nozzle

orientation was possible. Hence the angular increments were accomplished by rotation of the model while

the PIV optical system was kept fixed in a vertical orientation. Data was acquired on the lower half of the

jet with the field of view allowing data to be processed starting roughly 0.5 inch (0.012m) above the

centerline. Each radial plane was acquired in a separate test run, often run on different test days. This

decreased the quality of the match when the planes were assembled in post processing, especially since the

rig is known to thermally grow in an inconsistent manner.

NASA/TM—2002-211366 11
An additional complication comes from the fact that the light sheet must be slightly moved off the plane of

symmetry so that the flare from the model does not burn the camera sensor. By moving the light sheet

approximately 2mm away from the camera, the light reflected from the model is directed away from the

camera; or put another way, the camera cannot see the place on the model where the light sheet makes

impact. This slight modification should be kept in mind when comparing data close to the model. It should

also be noted that the model has been known to move about by 1-2mm over a period of several minutes due

to thermal loading, making precise location of the sheet relative to the model rather difficult.

Figure 5.1 graphically indicates the axial and angular grid used.

Figure 5.1. Orientations of measurement planes.

NASA/TM—2002-211366 12
5.1.5 Spatial limitations

The axial traverse was limited to 96 inches (2.4m) of travel. Further, due to optical restrictions and image

resolution issues, the widest field of view that could be accommodated was 5.5 inches (14cm) square. By

dividing up the axial traverse into 5 inch (12.7cm) increments with 0.5 inch (1.3cm) overlap between

frames, the total plane of data could be acquired in 19 segments. By using two cameras mounted one atop

to the other a total field of view 5.5inches (14cm) wide by 10.5inches (26.7cm) tall could be acquired. The

lower part of Figure 5.1 shows how the longitudinal measurement plane was segmented into the 2 by 19

overlapping fields.

5.1.6 Other limitations

Due to limitations in the amount of image data that could be stored on the PIV acquisition computer

(roughly 60GB uncompressed), only two complete data planes could be acquired on a given day. This filled

two of the three disk drives, leaving the third to store the compressed images that were sent over the local

ethernet to other computers for processing. Due to these limitations, of the seven planes per nozzle desired,

only three, the 0°, 15°, and 30° angles, were full length. The other four planes were only measured for half

the axial length as it was determined that the angular variations were minimal downstream of that point.

Thus it should have taken roughly two and one-half test days to acquire the data for one nozzle. Of course,

rarely did a test day go perfectly (see Test Narrative).

5.2 Models tested

5.2.1 3BB—Axisymmetric baseline nozzle

Model 3BB was the baseline nozzle, being axisymmetric on both core and fan nozzles. This model

represented a generic separate flow nozzle such as are flying on medium twin engine commercial transports

today.

The plug angle is approximately 16°. The core cowl exit diameter is 5.156 inches (13.09cm) measured cold

and the core cowl external boattail angle is approximately 14°. Also, at cold conditions, the core cowl exit

plane is 4.267 inches (10.84cm) downstream of the fan nozzle exit plane.

An assembly drawing of this model and a photo are given in Figure 5.2.

Figure 5.2. Nozzle 3BB. (a) Cross section of model nozzle system. (b) photo of assembled nozzle

in NATR.

One important note on a significant imperfection in the model system is in order. It was determined after

the test that the models had a significant droop, creating a slightly nonsymmetric flow field. Figure 5.3 and 

NASA/TM—2002-211366 13
Table 5.2 documents this asymmetry. This is important to keep in mind when comparing centerline data

from these measurements with other data or simulations. Differences between the models is relatively

unaffected by this droop.

Figure 5.3. Measured deflections in model parts, measured after PIV runs.

Table 5.2. Measured angles of model and traverse.

Part top bottom average design droop

Plug: 17.5° 14.9° 16.2° 16° 1.3°

Core: 15.0° 13.0° 14.0° 14° 1.0°

Fan: 14.7° 13.3° 14.0° 14° 0.7°

Freejet: --- 0.1° --- 0° 0°

Traverse: --- -0.3° -0.3° 0° -0.3°

5.2.2 3A12B—Alternating 12-count chevron core nozzle with axisymmetric fan nozzle

Model 3A12B substituted an alternating chevron trailing edge on the core nozzle for the axisymmetric one

of 3BB. Chevrons can be thought of as being cut into the otherwise axisymmetric nozzle to have the

baseline throat at the half height of the chevrons. Basic chevrons follow flow lines of baseline nozzle past

throat. The alternating chevron core nozzle can be thought of as starting from a flow–aligned chevron

design with half of the chevrons being bent into the core stream approximately 4.5° with a small additional

cusp to the chevron. The other half of the chevrons are bent into the fan stream by roughly 8°. Penetrations

were intended to extend 2 boundary layer heights into the flow. More details about the original design

philosophy and acoustic performance are given in reference 4, the report on the 1997 SFNT generated by

GEAE, the designers of this nozzle. The result is a mean core flow with a six-sided star-shaped crosssection shortly downstream of the plug.

Although its thrust coefficient was reduced by roughly 0.5% by the addition of the chevrons (reference 1),

this nozzle produced roughly 3dB suppression at the takeoff power condition. Because of the extreme

change in both mean flow profile and far-field noise produced by the alternating chevron design, this model

was chosen for detailed PIV measurements.

An assembly drawing of the model and a photo are given in Figure 5.4.

NASA/TM—2002-211366 14
Figure 5.4. Nozzle 3A12B. (a) Cross section of model nozzle. (b) photo of assembled nozzle in

NATR.

5.2.3 3T24B—24 count alternating tabbed core nozzle with axisymmetric fan nozzle

Model 3T24B substituted an alternating tab trailing edge on the core nozzle for the axisymmetric one of

3BB. Two aspects of the tab design distinguish it from the chevron design. First, the tabs protrude into the

flow from the nominal flow alignment starting with a hard break, not a gradual bend. The tabs make an

angle of approximately 45° with the flow, making a significant blockage of the flow. Second, in alternating

the tab bending pattern, six of the tabs were bent inward, 6 were bend outward, and 12 were left aligned

with the flow. This six-count pattern then again resulted in a mean core flow with a six-sided star-shaped

cross-section shortly downstream of the plug.

Although its thrust coefficient was reduced by roughly 1.0% by the addition of the tabs, the 3T24B nozzle

produced roughly 3dB suppression at the takeoff power condition. However, it produced much greater

mixing than the 3A12B model, suppressing low frequency more, but producing more high frequency noise

in balance. Because of the extreme change in both mean flow profile and far-field noise produced by the

alternating tab design, this model was chosen for detailed PIV measurements.

An assembly drawing of the model and a photo are given in Figure 5.5.

Figure 5.5. Nozzle 3T24B. (a) Cross section of model nozzle. (b) photo of assembled nozzle in

NATR.

6 PIV Instrumentation

6.1.1 Big Blue traverse

For this test the PIV system was totally carried on the large AAPL traverse. This traverse, known as

BigBlue (Figure 6.1), has had two tables added to its original frame, one on each side of the flow. The

NASA/TM—2002-211366 15
traverse can actuate a set of vertical rakes across the flow while the entire frame rolls along a track in the

axial direction. For this test, the PIV equipment was simply translated axially by the leadscrew attached to

the floor. By using anti-backlash actuation the axial traverse maintains a position accuracy of ±0.04 inches

(±0.001m) over a traverse distance of 96 inches (2.4m). The traverse was controlled by the Precision

Actuation Control System (PACS) software created at Glenn for this purpose. Two additional tables were

built onto BigBlue to carry the laser and the cameras together. Newport X95 rails and clamps were used,

along with MicroBench optical mounts to position laser optics and cameras.

Figure 6.1. Big Blue. Traverse for moving PIV system to different measurement locations.

6.1.2 Optical layout

 A series of mirrors and lenses directed the laser beam from the double-headed pulsed Nd:Yag laser into a

vertical light sheet aligned with the flow axis. The laser was mounted transverse to the rig at the front of

BigBlue, outboard of the main frame, at a level well below the freejet. This same table carried the power

supplies, data acquisition computer, and syncronizer hardware. A small roof was built over this table to

protect from rain coming in through the AAPL vent fan located directly overhead. Figure 6.2 shows how

the optical components were laid out on the traverse.

From the laser head the beam was directed along the lower frame rail of BigBlue to the centerline of the rig

where it was directed upward by a 45° mirror. A 2m focal length uncoated spherical lens was placed just

before this mirror, 60 inches (1.52m) before the beam crossed the rig centerline. A -40mm focal length

cylindrical lens was placed 4 inches (10cm) above the mirror, to create the light sheet. The light sheet was

flared to a 13.5 inch (340mm) by 0.025 inch (0.6mm) cross-section at its waist, located nominally at the jet

centerline. By the time the light sheet impacted the dome ceiling its cross-section was approximately 8 feet

(2.4m) wide, making the energy load on the fiberglass wedges and vent fan structure entirely safe.

NASA/TM—2002-211366 16
Figure 6.2. Optical layout on BigBlue.

6.2 Laser, cameras, frame grabber

6.2.1 Laser specs

A dual head Nd:YAG laser operating at 532 nm was used to generate the 400 mJ/pulse light sheet. The

laser pulses were synchronized with the cameras and frame-grabbers using TSI’s Insight (Version 3.2)

software and Synchronizer. The Synchronizer controlled the timing of the pulsed light source relative to the

CCD camera frame transfer period. Image frame pairs are obtained by straddling adjacent frame

boundaries. A PCI frame digitizer was used to acquire image data directly to disk in 400 image sequences.

6.2.2 Camera specs

Two cameras were used together in this setup, being treated by the controlling software as if they were

being used for stereo PIV even though they had independent fields of view. The cameras were mounted one

atop the other 52 inches (1.32m) away from the light sheet. Each camera was a 1000x1000 pixel Kodak ES

10 camera equipped with an f/5.6, 85 mm Nikkor lens and an 8mm extension ring. This combination

produced a 5.5 inch (0.127m) square field of view. The two cameras were positioned to overlap their fields

of view by 0.5 inches, yielding a composite field of view 10.5 inches high by 5 inches wide (0.267m x

0.127m).

NASA/TM—2002-211366 17
6.3 Acquisition parameters

PIV image frame pairs, required to produce an instantaneous velocity map, were acquired primarily at a

time separation of 2.2 microseconds. This was done to accommodate the expected out of plane motion,

instantaneously as high as 150m/s, with a light sheet 0.6mm thick. Previous experience with PIV in jets

showed that out of plane motion was a limiting factor in obtaining accurate results. To test this

understanding, limited data points were acquired with 4 and 6 microsecond pulse delays (presented in

section 5.3). 400 image pairs were recorded by each camera at each location.

7 PIV Analysis

7.1 Image Processing

Measuring a single plane of data 95 inches (2.4m) by 10.5 inches (0.27m) required 30,400 images, each

8bit monochrome image of 1024 by 1024 pixels taking 1MB. Storing, transporting, and processing of this

volume of data is an enormous task with current computer resources.

7.1.1 PIVPROC

The collected PIV image data were processed using an in-house developed code. An in-house image

processing package, PIVPROC, uses fuzzy logic data validation to ensure that high quality velocity vector

maps are obtained [7]. The correlation based processing allows subregion image shifting, asymmetric

subregion sizes and multi-pass correlation processing.

7.1.2 Grid determination, scaling

A grid was constructed, registered on the nozzle lip from the first frame image, so that velocities computed

from each image would create a uniform map. Five velocity grid cells overlapped in the radial direction and

three in the axial direction. A multipass scheme was employed, using first a 64 by 64 pixel region to

determine mean shift of images, followed by a 32 by 32 pixel pass with 50% overlap between grid cells.

The 32 by 32 pixel grid corresponded to a 0.088 inch (2.24mm) grid size in physical space.

7.1.3 Acceptance criteria for vectors

The procedure for computing statistics from a series of processed PIV image velocity vector maps utilizes

several acceptance criteria to qualify vectors and identify and remove incorrect vectors: signal to noise

ratios for the image correlation, hard velocity cutoff limits and an automated procedure for identifying

outliers. In the data processing done here, the peak signal to noise criteria for the correlation/peak detection

was set to 1.5. The high and low velocity cutoff limits were set to -150m/s and 600 m/s for the axial

component, and ±150m/s for the radial. Next, the mean and standard deviation are computed at each grid

point in the velocity vector map. The automated procedure for removing outliers is based on Chauvenet’s

criterion (Taylor 1982), in which the probability of occurrence of a given point deviating from the mean is

computed. The main assumption here is that the parent velocity distribution is Gaussian. The number of

standard deviations that a given point lies from the mean is first computed. Then the probability that a

given point could deviate from the mean by this many standard deviations is computed from the normal

error integral and multiplied by the number of points in the distribution. If the computed probability is less

than a preset level (in this case 3%) then the point is removed.

In all data presented from this test, a relative data 'quality' metric is the number of accepted velocity vectors

at a point. If no vectors are rejected, this number would be 400, the same as the number of image pairs

acquired. Typically, this value is between 380 and 400.

NASA/TM—2002-211366 18
7.2 Definition of turbulence statistics 

7.2.1 One-point statistics 

Following standard turbulence practice [8], subdivide the instantaneous velocity vector !

u into time mean and 

instantaneous parts: 

( , ) ~ u(x,t) U(x) u x t ! ! ! ! ! ! = +

where 

( ) ( )

1 ~ ( ) 0

u x dt u x

T

U x

T ! ! ! ! ! ! = = ∫ 

is the time average velocity, denoted by the brackets. Then the mean square of the fluctuating part, e.g. the 

variance of velocity, can be defined 

∫ = − T

U x u x dt

T

u x

0

2 2 ( )) ~ ( ( )

1

( ) ! ! ! ! ! ! . 

Taking the square root of the variance gives the root mean square (rms) of the fluctuating part of the velocity. 

Because of the way data was acquired in radial planes, we should choose a cylindrical polar coordinate system with 

axial, radial, and polar coordinates in that order: 

 

!

x = (x,y,θ); 

!

u = (u,v,w). 

In this system, measurements were taken in the axial (x) and radial (y) planes and only the axial and radial 

components of velocity (u, v) were measured. However, because of the way data three-dimensional visualization 

packages work, many of the graphs show a Cartesian coordinate system. Just remember that data is actually taken in 

polar coordinates and that the y-coordinate and v-component of velocity refer to a radial plane. 

Likewise, for notational convenience in the graphs, the following notation was adopted: 

mean values u(x) ! ! are denoted by <U>, <V>, 

variances ( ) 2 u x ! ! are denoted by <u^2>, <v^2>. 

7.2.2 Two-point statistics 

Our interest in two-point statistics is driven by aeroacoustic theory. Specifically, aeroacoustic theory requires 

knowledge of spatial correlations of the velocity field: 

(ξ, ) = ( + ξ / 2) '( − ξ / 2) ! ! ! ! ! ! ! ! R x u x u x

where !

ξ is a small displacement about the spatial point !

x . This quantity has five terms (assuming symmetry) in 

three spatial dimensions for every point in physical space. Since we only have two components of velocity in a 

plane, we only can compute three of the five components in two dimensions in a plane. Notationally, we compute 

<uu'>(ξ1, ξ2; x,y), 

<uv'>( ξ1, ξ2; x,y), 

<vv'>( ξ1, ξ2; x,y), 

for displacements !

ξ =( ξ1, ξ2, ξ3), where ξ3 is dropped, data being only in the radial plane. 

The correlation is normalized in our data by the root mean squares at the reference point, 

NASA/TM—2002-211366 19
( ) ' ( )

( / 2) '( / 2)

( , ) ~

2 2 u x u x

u x u x

x ! ! ! !

! ! ! ! ! !

! ! + ξ − ξ

R ξ =

which is different from the oft-used normalization 

( ) '( )

( / 2) '( / 2)

u x u x

u x u x

! ! ! !

! ! ! ! ! ! + ξ − ξ

. 

The latter expression is not useful in flows where U2 is near zero, as it is on the jet centerline. 

In contour plots of the two-point correlation, the correlation of the field with a given reference point is shown by 

( ) ' ( )

( ) '( )

'( , ) ~

2 2 + ξ

+ ξ

ξ ! ! ! ! !

! ! ! ! !

! !

u x u x

u x u x

R x . 

In these cases, symmetry may not be assumed and both permutations <uv'> and <vu'> are shown. 

Models for two-point correlations have traditionally been developed by assuming a functional form separable in 

space and time. From the equations of motion certain constraints apply (Batchelor) 

∂ ξ

∂ =





















ξ

ξ ξ δ − 

















 ξ ξ = +

= ξ τ

f f

f f R f

R g

u

u u

i j

ij ij

ij

i j

, ' 2

'

2

' ( )

( ) ( )

'

2

1

!

!

A popular analytic model for the two-point spatial correlation is the Gaussian form 

( ) 

















 −π ξ

ξ =

2

2

L

f e

yielding the forms 

( )

( ) 

















 −π ξ



















 −π ξ



















 πξ + πξ ξ = −



















 πξ + πξ ξ = −

2

2

2

2

2

2

3

2

1

22

2

2

3

2

2

11

1

1

L

L

e

L

R

e

L

R

!

!

When compared against current data, the Gaussian form seems a poor fit—the correlation does not seem to have a 

zero derivative at ξ = 0, instead dropping much faster. Theoretically, the correlation must have a zero derivative at ξ

= 0 [9], in fact the second derivative (curvature of the correlation at the origin) here is the Taylor microscale, 

associated with the finest scales of motion. Contrast this with the largest lengthscales of motion, defined by the 

integral of the correlation curve, and we see why, for this large Reynolds number, the Taylor microscale is so much 

smaller than the integral lengthscale—the curvature at the origin cannot be seen in the experimental data. Modifying 

the model above by changing the power of the exponent, setting 















 −πξ

ξ = 2

2

( )

L

f e

produces a more satisfying fit to the data, as was found by Frenkel[10] and Laurence [11]. 

NASA/TM—2002-211366 20
Another part of the popular model that does not agree with data is the assumption of isotropy. Indeed, it has been 

found that the the two cross-stream turbulence intensities are nearly equal, but are less than the axial turbulence 

intensity. For this reason an axisymmetric turbulence model is examined. Referencing Khavaran [12], the 

axisymmetric model with Gaussian decay is given by 

uu Q

uu Q

Q

Q

u

e Q u ue

L

L

L

LL LL

i i

11 1 2 3

22 3

2

2

2

3

2 2

1

2 2 2

1

2

3

2

1

1

1

2

2 2

2

1

2

2

2

1

2 1

1 2

2 1 2 12 21

2

1

2

1

2

2

2

3

2

2

2

1

2

1

2

2

2

3

2

2

2

' ()

' ()

;

;

!

!

ξ

ξ

π ξ

π ξ ξ ξ π ξ ξ ξ

=− − −

=−+

+ −−− + +−+ + −+ F

H IK

=− = −

= =

− + F +

H

G I

K

J − + F +

H

G I

K

J

Χ Χ

Χ

∆Χ ∆Χ ∆ ΧΧ

Χ ∆

b g

d i

e je j e j

e j

An axisymmetric model with single-power exponential decay is given by 

uu Q

u u

Q

L

L Q

Q

u

e Q u ue L L

11 1 2 3

2 2

2

3

2 2

2

1

2 2 2 2 2

2 3

2

3

2 2

2 2

2

3

2 1

1

1

2

2 2

2

1

2

2 1

2

2

8 24 1 1

4

4

2

1

2

1

2

2

2

3

2

2

2

' ()

' ()

( )

;

!

!

ξ

ξ π

γ π γ γ π πγ

γ π

γ

π ξ ξ ξ

=− − −

= +

+ + − + −+ +−+ F

H IK

F

H

G I

K

J F

H

G F

H

G

+ −+ + I

K

=− = −

− + F +

H

G I

K

J −

Χ Χ

Χ

Χ ∆ ∆ ∆Χ

Χ ∆ΧΧ

b g

e j

e j

e jj d i

e j π ξ ξ ξ

π

γ

ξ γ ξξ ξ

1

2

1

2

2

2

3

2

2

2

2

2

1

2 2

1

2

2

2

3

2

L L

i i L

L

L

+ F +

H

G I

K

J

Χ ∆∆ = = = ++ ; ;

7.2.3 Integral Lengthscales 

In modeling the two-point spatial velocity correlation, it is often assumed that there is some displacement over 

which the velocities become uncorrelated. One definition of this is the integral lengthscale L 

 

L(

!

x ) = R(

!

ξ ,

!

x )dξ

0

∞

∫ , 

which happens to nicely match the scaling exponent L of the Gaussian form. One can still apply the same definition 

for L to cases where the flow is not isotropic. However, computing this integral with discrete data over a finite 

range, such as is obtained in experiments, does introduce a significant uncertainty in the measure of L. Fitting a 

reasonable functional form to the data and integrating it yields a cleaner statistic. After looking at all the correlation 

data, the Gaussian model does not seem to be the best fit to the data; instead, the data was fitted to the single-power 

exponent expressions that do fit the data much better. Figure 7.1 illustrates the relative fits between single 

exponential and Gaussian expressions. Also given in the figure, but only showing up in the Rvvx component, are 

curve fits for both isotropic and axisymmetric models of the single and double exponential forms. 

NASA/TM—2002-211366 21
(a) (b)

(c) (d)

Figure 7.1 Two-point spatial correlations with single and double exponential forms fitted to the

data.

Operationally, four fits to the axisymmetric single-power exponential form were performed at every

evaluation point with the u(x,y), v(x,y) data, and four lengthscales determined:

- two estimates for L1, Iuux from <uu'>( 1) and Ivvx from <vv'>( 1).

- two estimates for L2, Iuuy from <uu'>( 2) and Ivvy from <vv'>( 2).

7.3 Analysis of error

7.3.1 First principle estimate of PIV accuracy

The accuracy of the velocity estimates is inversely proportional to the particle displacement between

exposures. The maximum displacement is restricted to 1/4 of the correlation subregion size, hence using a

correlation subregion size of 32x32 pixels yields a maximum measurable displacement of 8 pixels. The

correlation peak location in the PIV algorithm can nominally be estimated to within 0.1 pixels, yielding

measurement errors on the order of 1% of full scale for 32x32 pixel subregion processing. This translates to

an instantaneous, single frame uncertainty of 12m/s. Errors in first order statistics, such as mean velocity,

computed from N samples, scale as N-1, yielding an uncertainty of 0.04m/s in the mean velocity from PIV

processing itself. Second order statistics scale as N-1/2 giving an uncertainty in turbulence intensity of

0.6m/s. Again, note that this is the uncertainty due to the PIV processing itself; there are many other

factors, such as variation in seed densities, non-stationarity in the operation of the facility, etc. that will

increase this uncertainty.

7.3.2 Particle lag

One measure of the error introduced by the particle velocity not equaling the fluid velocity is the particle's

frequency response which quantifies how fast the particle moves in response to a change in the fluid

velocity. The frequency response and particle lag distance behind an oblique shock for various seed

materials has been reported by Melling [13]. Simple application of Melling’s results show that the

frequency response of a particle of diameter dp and density p in a fluid with viscosity μf would be

Using these results, the seed particles used here would have a frequency response of 35kHz. This can be

interpreted as a low-pass filter on the velocity data and was most noticeable as a loss of particles in the

cores of vortices just downstream of the chevrons in some planes.

2 10

18

pp

f

ρ d

μ

NASA/TM—2002-211366 22
7.3.3 Loss of data

Another major factor leading to loss of accuracy in PIV turbulence measurements is the loss of some

velocity vectors due to image errors, manifest in signal to noise ratio. This can result from error in camera

focus, from having too few or too many particles in a correlation region, from particles moving into or out

of the light sheet between light pulses, from particle images too fine to be resolved in the digitized image,

from stray light from model glare, and from large velocity gradients across the interrogation region. This

error is generally caught in the acceptance stage of processing and results in lower data quality statistic, the

number of accepted vectors out of all images acquired. However, in regions where the data quality is

relatively low, there is reason to suspect that the acceptance schemes did not remove all spurious data. For

instance, one of the acceptance schemes, Chauvenet's criteria, uses the variance of the data itself as a

measure of how much variance to allow in the distribution of values. Bottom line: if turbulence statistics

seem out of line in regions where the data quality is poor it probably should not be trusted. Not many

regions of the current test dataset have this problem. The main problem area is in the vectors right next to

the model where reflection was a problem, and near the edges of the images where diffraction of the image

mask in the camera may have removed some particle images from the interrogated region, leaving too few

particles. In this test there was no correlation of poor data quality with regions of high out of plane velocity.

This indicates that the two components of velocity vectors measured are not biased by removal of data with

high out of plane component.

7.3.4 Direct test of t error

One direct test of the out of plane error and of the accuracy limits imposed by the choice of maximum

displacement is to increase this maximum displacement by increasing the time delay between laser pulses

and observing how the flow statistics change. To this end, data was acquired in the 3BB nozzle at the exit

plane of the core nozzle at three different time delays—2.2μs (standard), 4μs, and 6μs. Figure 7.2 shows

the location of the line where the data being examined was acquired. The changes in the data quality, the

mean velocity profiles, and the variance in axial and radial velocities are plotted in Figure 7.3 for the three

different time delays.

Figure 7.2. Location of radial line for t example.

NASA/TM—2002-211366 23
(a) (b)

(c) (d)

Figure 7.3. Measurements taken with three different t between laser pulses. (a) Data quality, (b)

mean axial velocity, (c) variance of axial velocity, (d) variance of radial velocity.

In Figure 7.3a, the data quality in the core/fan shear layer (y -0.1m) drops with increased time delay,

probably due to an increased occurrence of out of plane motion. However, the data quality is near perfect in

other regions, except for y > -0.05m, where the mean displacement is simply too great at t = 6μs for the

interrogation region. Differences in mean axial velocity in Figure 7.3b are less than 1% in the fan flow and

less than 0.1% between the 2.2μs and 4μs data. The differences between the curves in the shear layers is

probably due to known problems with the model moving slightly during operation, shifting the location of

the shear layer over times of the order of minutes.

Differences in the variances of the velocity (Figure 7.3c,d), especially in the core/fan shear layer at (y -

0.1m) lead to a question of which is the worse source of error: increased uncertainty in each velocity

measurement with small t, or increased possibility of false acceptance of bad data with larger t and out

of plane motions. Combined with the data quality plot in Figure 7.3a, it would seem that the latter is clearly

a problem for the t=6μs data, while its effect on the 4μs data is unclear. The difference in uncertainty

between the 2.2μs and 4μs data are large, but given the data quality plots, the 2.2μs data seems most

reliable. Thankfully, most of the measurement region has data quality well in excess of that found in this

portion of the core/fan shear layer.

NASA/TM—2002-211366 24
8 Presentation of Data

This chapter is mostly an orientation to the graphical presentation of the data, and it also describes the file

format of the numerical datafiles to aid users who are wanting to extract the data for their own purposes.

Appendix A contains the graphical presentation of the data.

8.1 Organization of figures

The figures are organized first by nozzle geometry (baseline, 3A12B, 3T24B). Then the data is shown in two

separate groups of figures, the first presenting the data from oblique view to aid in orientation and

perception, the second presented as planar cuts for more quantitative comparisons. Inside the oblique view

section all the statistical properties are shown, first the one-point statistics and then the two-point statistics.

Inside the planar cut section, all the statistics are presented together for each cut. The integral lengthscale

statistics are only shown in these planar cuts.

8.2 Data format of digital data

The raw velocity maps, comprising 400 vector fields per location, are stored as tab-delimited files and are

not available due to logistical constraints. The statistics computed from these maps, presented graphically

in Appendix A, are available as plot3D files [14]. They are in formatted, 3D, scalar files along with the

corresponding grid file. There are typically 1080 axial by 115 radial grid points for the 0°, 15°, and 30°

planes. There are 513 axial by 115 radial grid points for the 5°, 10°, 20°, and 25° planes. The following

files are available for the 3BB, 3A12B, 3T24B nozzles:

One-point statistics, filenames

Model 3BB 3A12B 3T24B

Grid 3bbx.x 3abP.x 3tbP.x

<u>(x,y,q) 3bbx.U 3abP.U 3tbP.U

<v>(x,y,q) 3bbx.V 3abP.V 3tbP.V

<u><v>(x,y,q) 3bbx.UV 3abP.UV 3tbP.UV

<u^2>(x,y,q) 3bbx.u 3abP.u 3tbP.u

<v^2>(x,y,q) 3bbx.v 3abP.v 3tbP.v

<uv>(x,y,q) 3bbx.uv 3abP.uv 3tbP.uv

number good points

out of 400

3bbx.N 3abP.N 3tbP.N

Note: 'P' is replaced

by letter to designate

plane:

'a' -- 30°

'b' -- 25°

'c' -- 20°

'd' -- 15°

'e' -- 10°

'f' -- 5°

'g' -- 0°

Two-point statistics, filenames

Model 3BB 3A12B 3T24B

Grid 3bbx.x 3abP.x 3tbP.x

<uu'>(x,y,q) 3bbx.uu 3abPrR.uu 3tbPrR.uu

<uv'>(x,y,q) 3bbx.uv 3abPrR.uv 3tbPrR.uv

<vu'>(x,y,q) 3bbx.vu 3abPrR.vu 3tbPrR.vu

NASA/TM—2002-211366 25
<vv'>(x,y,q) 3bbx.vv 3abPrR.vv 3tbPrR.vv

Note: 'P' is replaced

by letter to designate

plane:

'a' -- 30°

'b' -- 25°

'c' -- 20°

'd' -- 15°

'e' -- 10°

'f' -- 5°

'g' -- 0°

Note: 'R' is replaced

by letter to designate

reference point:

'0' -- y = 0.00"

'1' -- y = 0.03"

'2' -- y = 0.06

'3' -- y = 0.09

'4' -- y = 0.12

'5' -- y = 0.15

'6' -- y = 0.18

'7' -- y = 0.21

'8' -- y = 0.24

Lengthscale statistics, filenames

Model 3BB 3A12B 3T24B

Grid 3bbxls.x 3abPls.x 3tbPls.x

L1(x,y,q) 3bbxls.luux 3abPls.luux 3tbPls.luux

L2(x,y,q) 3bbxls.luuy 3abPls.luuy 3tbPls.luuy

L1(x,y,q) 3bbxls.lvvx 3abPls.lvvx 3tbPls.lvvx

L2(x,y,q) 3bbxls.lvvy 3abPls.lvvy 3tbPls.lvvy

Note: 'P' is replaced

by letter to designate

plane:

'a' -- 30°

'b' -- 25°

'c' -- 20°

'd' -- 15°

'e' -- 10°

'f' -- 5°

'g' -- 0°

9 Summary of Results

This is a minimal “what do we see in the data” chapter. More analysis of the results will be done in followon papers; this paper is supposed to be a documentation of the experiments and of the data.

9.1 Comparisons with Plume Survey Measurements

There are few if any previous measurements of the velocity field of a separate flow nozzle operating with

hot core in a simulated flight environment—that was the point in taking these measurements! However, we

can compare the mean velocity fields measured with the PIV system with those found using standard

pressure and temperature rake technology. Total pressure and total temperature measurements were made

of these nozzles in the 1997 test, and are brought out to compare with current PIV data. It is known that the

1997 plume rake data is somewhat flawed because it assumes that static pressure is constant. This was

shown to give velocities that were low by up to 10% near the nozzle, and even being 5% low by 0.3m

downstream. Although the plot at this scale does not show it, detailed examination of the two data sets

bears out this difference with the two agreeing to within 10%. The majority of the discrepancy is due to the

nozzle droop in the PIV data, a feature introduced into the model during reassembly of the model in 2000.

NASA/TM—2002-211366 26
Figure 9.1. Comparison of mean axial velocity as calculated from Pt, Tt (1997; top), and as

measured using PIV (2000; bottom).

9.2 Comparisons with Computational Results 

As part of the Advanced Subsonic Technology program in 1997, a contract was let by NASA to compute Reynolds 

averaged Navier-Stokes (RANS) solutions for the flows from selected SFNT nozzles. Under this contract, 

Combustion Research and Flow Technology, Inc. (CRAFT, Inc), computed the flow field of the three nozzles 

studied in this report. Details of this computation are found in [15]. 

In the following three figures the predicted flow fields for the 3BB nozzle are shown in the upper half of the plume 

while the data are shown in the lower half. It must be noted that the experimental data overlays the centerline by 

0.01m and slightly biases the eye on the centerline. Figure 9.2 gives the comparison for the mean velocity fields, 

where the main difference seen is that the actual nozzle had a droop and the wake of the centerbody drops 

downward. Decay of the high speed core flow is properly predicted and the spread is also well matched. Figure 9.3, 

the comparison of radial mean velocity, is included for completeness, although it could be argued that the flow at the 

nozzle is very easy to predict and that the differences downstream are not visible at this contour scale. In actuality, 

the experimental error in finding zero radial velocity is as great as the differences between the two radial velocity 

fields. 

Figure 9.4 compares turbulence kinetic energy as predicted by the CRAFT RANS code and as measured by the PIV 

system. There are two aspects of this figure which require discussion. First, turbulence kinetic energy, strictly 

speaking, is defined as 





 



 ++= 2

3

2

2

2

1 2

1 uuuk . 

Because the CRAFT RANS code, like most other compressible RANS codes, are formulated in Favre-averaged 

variables, e.g., with density-weighted primitive variables u

! ρ , the turbulent kinetic energy from the prediction is 

actually 





 



 ρ+ρ+ρ

ρ = 2

3

2

2

2

1 2

1 uuuk . 

The slight difference, that the prediction values include the correlation of density fluctuations, will create a slight 

difference in the value of k, especially given the temperature variations that exist instantaneously. 

Another approximation made in constructing the figure, this time from the experimental data side, is the assumption 

of axisymmetry in the turbulence. It has been noted in earlier LDV measurements that the <v^2> and <w^2> terms 

are nearly identical in an axisymmetric jet [16]. This assumption is used here to provide the missing <w^2> term in 

κ for the experimental data shown in the lower half of Figure 9.4. 

With those two caveats in mind, the prediction of κ can be said to have its region of peak intensity within 10% of the 

right magnitude, but this region is too far downstream and is too small. The data shows a region of κ > 2500m2

/s2

spanning from 1 to 2.25 m downstream, while the comparable region in the prediction spans only from 1.75 to 2.5m. 

So while the CRAFT solution is a good prediction of mean velocities and jet spread, it seems to underpredict the 

region of maximum turbulent kinetic energy, the caveats regarding the quantities being compared notwithstanding. 

NASA/TM—2002-211366 27
Figure 9.2. Comparison of axial mean velocity, CFD Reynolds averaged Navier Stokes solution of

[15] on top, PIV data on bottom.

Figure 9.3. Comparison of radial mean velocity, CFD Reynolds averaged Navier Stokes solution

of [15] on top, PIV data on bottom.

Figure 9.4. Comparison of turbulent kinetic energy, CFD Reynolds averaged Navier Stokes

solution of [15] on top, PIV data on bottom. See note in text regarding definitions.

10 Summary

Detailed turbulence statistics were measured in three external plug, bypass ratio 5, separate flow nozzles

operating at a typical take-off condition with simulated flight of 0.3 Mach. The nozzles in the study were

ones whose acoustic fields had been extensively studied previously and had shown significant noise

reduction. The three nozzles were an axisymmetric baseline, an alternating 12 chevron design on the core

nozzle, and an alternating 24 tab design on the core nozzle. Instantaneous velocity maps were acquired

using PIV and statistics, including mean, variance, two-point correlation, and integral lengthscale, were

computed from these velocity maps. The turbulence statistics will be used to better understand what aspects

of the unsteady flow field give rise to noise and what measures are useful in reducing this noise.

The main point should be taken from this work: particle image velocimetry works well in acquiring

turbulence data in hot, high speed jets.

NASA/TM—2002-211366 28
11 References

 

1 Saiyed, N., Mikkelsen, K.L., and Bridges, J., 2000, "Acoustics and Thrust of Separate-Flow Exhaust

Nozzles With Mixing Devices for High-Bypass-Ratio Engines," NASA TM 2000-209948.

2 Saiyed, N., ed., 2000, "Separate Flow Nozzle Test Status Meeting," NASA CP 2000-210524.

3 Low, J.K.C., Schweiger, J.C., Premo, J.W., and Barber, T.J., 2000, "Advanced Subsonic Technology

(AST) Separate-Flow High-Bypass Ratio Nozzle Noise Reduction Program Test Report," NASA CR 2000-

210040.

4 Janardan, B.A., Hoff, G.E., Barter, J.W., Martens, S., Gliebe, P.R., Mengle, V., and Dalton, W.N., 2000,

"AST Critical Propulsion and Noise Reduction Technologies for Future Commercial Subsonic Engines

Separate-Flow Exhaust System Noise Reduction Concept Evaluation," NASA CR 2000-210039.

5 Long, M.J., 1992, “Experimental Investigation of an Ejector-Powered Free-Jet Facility,” NASA TM105868.

6 Castner, R.S., 1994, “The Nozzle Acoustic Test Rig: An Acoustic and Aerodynamic Free-Jet Facility,”

NASA TM 106495.

7 Wernet, M.P., 1999, “Fuzzy Logic Enhanced Digital PIV Processing Software,” NASA TM 1999-209274.

8 Bradshaw, P, ed., 1978, Topics in Applied Physics: Turbulence, Springer-Verlag.

9 Hinze, J.O., 1951, Turbulence: An Introduction to its Mechanism and Theory, McGraw-Hill, p. 54.

10 Frenkiel, F.N. 1948, J. Aeronautical Science 15, 57.

11 Laurence, J.C. 1956, “Intensity, Scale and Spectra of Turbulence in Mixing Region of Free Subsonic

Jet,” NACA report 1292.

12 Khavaran, A 1999, “Role of Anisotropy in Turbulent Mixing Noise,” AIAAJ 37, 832.

13 Melling, A 1997, “Tracer Particles and Seeding for Particle Image Velocimetry,” Measurement Science

and Technology 8, 1406.

14 Walatka, B. & Buning, P., 1989, “Plot3D User’s Manual,” NASA TM 101067.

15 Kenzakowski, D.C., Shipman, J., & Dash, S.M., 2001, “Task 2-Flow Solution for Advanced Separate

Flow Nozzles Response A: Structured Grid Navier-Stokes Approach," NASA CR 2001-210611.

16 Podboy, G.G., Bridges, J., Saiyed, N., & Krupar, M.J. 1995, “Laser Doppler Velocimeter System for

Subsonic Jet Mixer Nozzle Testing at the NASA Lewis Aeroacoustic Propulsion Lab,” NASA TM 106984.

NASA/TM—2002-211366 29
12 Appendix A: Test narrative

02.08.2000

Configuration: Jet Exit Rig has been reassembled and configured for laser testing. Aluminum oxide seed

will be injected into the core and bypass flows. The RFM in the core and bypass lines has been replaced

with choke plates. Charging station instrumentation has been replaced with older rakes from past programs.

The traversing rake is installed behind the JER.

Objectives: Check out the operation of the rig with the reticulated foam metal (RFM) removed and replaced

by choke plates. Compare data with previous runs to insure that the rig is performing as expected. Check

out new charging station rake instrumentation. Also, check out the operation of the traversing rake and the

effect of the freejet airflow on laser components mounted on the traverse rake shelves.

Results: Completed all objectives. The rig is performing the same as it did before the rebuild. traversing

rake was moved axially and the automated traverse system (PACS) profile was checked out. Facility data

acquisition system (Escort) acquired data automatically at each stopping point. The flow of the freejet

impinged on the camera and backplate mounted on the traversing rake. There was only slight movement

noticed of the camera's. A stiffening bracket will be added.

11.08.2000

Configuration: Same as previous.

Objectives: Check out the operation of the seeder carts for the core and bypass system. Measure the seed

flow with PIV laser to see if they are producing the right amount of seed.

Results: Run cancelled. Unable to align laser due to procedure specified in safety permit did not allow for

alignment of the laser with protective eyewear removed which is standard. Issue will be worked with the

laser safety office.

14.08.2000

Configuration: Same as previous.

Objectives: Check out the operation of the seeder carts for the core and bypass system. Measure the seed

flow with PIV laser to see if they are producing the right amount of seed.

Results: Complete checkout of the freejet smoke generator and bypass seeder cart. Both worked well and

produced enough seed for the laser to measure the flow field.

Problems: The core seeder cart did not produce seed consistently. After the solenoid valve is opened there

is a short duration of seed, then the supply pressure drops off and the seed stops. Will investigate further on

the next run.

15.08.2000

Configuration: Same as previous.

Objectives: Check out the operation of the seeder carts for the core and bypass system. Measure the seed

flow with PIV laser to see if they are producing the right amount of seed.

Results: Continued with troubleshooting the core seeder cart operation. As the pressure of the cart is

increased above the core line pressure that we are injecting seed into, the supply pressure of the cart

decreases until it matches core line pressure. No seed is produced.

Problems: The core seeder regulator works statically without any flow but drops off when connected to the

core air line. We suspect the supply solenoid valve is not opening completely.

16.08.2000

Configuration: Same as previous.

NASA/TM—2002-211366 30
Objectives: Check out the operation of the seeder carts for the core and bypass system. Measure the seed

flow with PIV laser to see if they are producing the right amount of seed.

Results: Still having difficulties getting the core seeder system to work properly we replaced the solenoid

valve which supplies air to the cart but had the same results. We also plumbed the system so that bypass

solenoid valve supplied both carts but again the core seeder would not supply seed.

17.08.2000

Configuration: Same as previous. Gate valves added to core and bypass seeder carts for back pressure the

regulators.

Objectives: Check out the operation of the seeder carts for the core and bypass system. Measure the seed

flow with PIV laser to see if they are producing the right amount of seed.

Results: fWe added regulators to the core and seeder carts which improved the range of control for the

bypass seeder; however, the core seeder still is not producing seed. For tomorrow's run we are swapping

pressure regulators between to the core and the seeder carts to see if that is the problem.

18.08.2000

Configuration: Same as previous.

Objectives: Check out the operation of the seeder carts for the core and bypass system. Measure the seed

flow with PIV laser to see if they are producing the right amount of seed.

Results: We finally had successful checkout of the core seeder. The problem was the solenoid valve that

supplied the cart was not opening fully and supply pressure was dropping off once flow started. The

solenoid valve was replaced earlier in the week so this was unexpected. We are replacing the solenoid

valve with an air operated ball valve which will serve the same purpose. PIV data acquired for nozzle 3BB

from the nozzle exit plane back to 90 inches in 5 inch increments. The data looked good and we are

proceeding with our test plan. However, fan stream screen just downstream of choke plates let go during

run. Tore down the rig and tried to repair screens by tacking back on (see Figure 13.1).

Figure 13.1. Repaired fan screen, with excess nichrome strips to strengthen screen near welds.

23.08.2000

Configuration: Same as previous. Fan flow straightening screens have been field repaired.

Objectives: Acquire PIV laser data at power cycle 21 conditions for nozzle 3BB. Move the traversing rake

axially from 0" to 90", stopping every 5 " to acquire laser data.

Results: Completed research objectives for nozzle 3BB. Time: 17:53-19:40

Problems: Had to shut down at 18:54 for more fogger oil. Back up at 19:30.

24.08.2000

NASA/TM—2002-211366 31
Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data.

Results: Started the run at 15:35. Seeders caked up at 14:01. Had to break the seed up with stick. In future,

only use dry seed, and clean out daily. Came up again, but fogger not turned on. Finished 3AB at 0°

clocking at 18:40. Came up on 3AB at 30° at 19:16 and finished at 20:48.

Completed the research objectives for nozzle 3A12B at 0 degree and 30 degree clocking.

25.08.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 40", stopping every 5" to acquire laser data.

Results: Started at 14:04. Finished by 15:47. Completed research objectives for nozzle 3A12B at 15°

clocking. Fan flow screens had ripped out again.

29.08.2000

Configuration: Same as previous. JER fan flow straightening screens removed. See Figure 13.2

Objectives: Verify the flow characteristics of the JER fan section with the flow straightening screens

removed. The screens have failed twice since we began laser testing and are removed. We need to

compare the flow of the fan section with the screens removed versus data we took with the screens in place.

Results: We acquired acoustics data with the fan screens removed for nozzle 3BB and 3A12B. Acoustic

data showed that chevrons were still providing 2+ EPNdB suppression, so it was deemed acceptable to

continue testing without fan screens downstream of choke plate.

PIV laser overtemp switch tripped out which prevented us from acquiring laser data.

Figure 13.2. Fan flow passage as seen from the nozzle exit with screen removed.

30.08.2000

Configuration:

Same as previous. Air conditioner added to direct chilled air onto laser power supplies.

Objectives: Verify the flow characteristics of the JER fan section with the flow straightening screens

removed. The screens have failed twice since we began laser testing and are removed. We need to

compare the flow of the fan section with the screens removed versus data we took with the screens in place.

Results: Acquired PIV laser data for nozzles 3BB and 3A12B. Data showed minimal impact from screens

being removed. See Figure 13.3.

NASA/TM—2002-211366 32
Had poor freejet seeding on the first run. Saw sparkles in the seeding indicating large droplets of oil.

Cleaned Vicount seeder nozzle between runs. Fogger worked better, no droplets. Put lots of oil on NATR

centerbody and framework in doghouse.

Took minimal data to look for problems with screen. First run from 17:32 to 18:00; second run 19:08

to19:55.

Figure 13.3. Comparison of fan stream freestream turbulence with and without screen in rig. Removal of

screen did not increase turbulence levels.

06.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 40", stopping every 5" to acquire laser data. Test the 3A12B nozzle at 5°, 20°, and 15° clockings.

Results: Acquired desired data. Long run of 3A12B @ 15° orientation took from 15:41 to 17:26. Short run

of 3A12B @ 5° orientation 18:15 to 19:00. Short run of 3A12B @ 20° orientation 20:04 to 21:42. Later

found that 5° data was not at 5°.

07.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 40", stopping every 5" to acquire laser data. Test nozzle 3A12B at 20°, and 30° clockings.

Results: Acquired desired data. Short runs:16:10 to 16:44 for 5° orientation, 17:07 to 18:25 for 20°

orientation, 20:25 to 22:29 for 30° orientation.

08.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Run nozzle 3A12B at 30° clocking and 3T24C at 0°

clocking.

Results: Acquired desired data. Long runs at 30° from 16:20 to 18:00 and at 0° from 18:25 to 20:29.

NASA/TM—2002-211366 33
11.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3T24C at 30° clocking.

Results: Laser beams went out of alignment during the run. There was not enough time to realign and

complete another data set so we will repeat the configuration tomorrow. Light sheets were found not to

overlap. Must confirm overlap every day!

12.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3T24C at 15° clocking.

Results: Acquired desired data. We had to shut down during the run due to an oil leak on the output valve

of the Central Air C16 compressor. The leak was repaired by the valve shop and the run resumed.

13.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 40", stopping every 5" to acquire laser data. Test nozzle 3T24C at 10°, 25°, and 30° clocking.

Results: Acquired desired data. Things are starting to get productive and boring.

14.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 40", stopping every 5" to acquire laser data. Test nozzle 3T24C at 5°, 10°, 25°, 3A12B at 25°, and

nozzle 3BB.

Results: Acquired desired data.

19.09.2000

Configuration: Same as previous. Setup PIV cameras in stereo mode.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3BB.

Results: Tried to do Stereo (3C) PIV. No good data was taken this day. Setups were a problem.

20.09.2000

Configuration Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3BB and 3A12B at 0° clocking.

Results: Set up cameras in Scheimplug configuration. Light sheet began to move and the left side of the

images was bad. Found that one camera had moved ALOT! Tightened it up and had it move again after the

second run. Again, no good data.

21.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3A12B at 30 degree clocking. Spot check

acoustic properties of new inward chevron fan nozzle. Run a matrix of 3 NPR's for nozzles 3BB, 3I12B,

3I12I24, and 3A12I24.

NASA/TM—2002-211366 34
Results: Cameras continue to move despite torqueing down on mounts. No good data.

25.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3BO with max area at the top of the nozzle and

3BB.

Results: Really clamped down on cameras using second beam and C-clamps. Camera didn't move

noticeably.

26.09.2000

Configuration: Same as previous.

Objectives: Acquire PIV laser data at power cycle 21 conditions. Move the traversing rake axially from 0"

to 90", stopping every 5" to acquire laser data. Test nozzle 3BO with max area at the bottom.

Results: Acquired desired data. Camera didn't move. Data may be good. This completes the PIV laser phase

of the Separate Flow Nozzle program.

NASA/TM—2002-211366 35
13 Appendix B: Data plots

Appendix B contains 384 plots of turbulence statistics rendered from the data.

NASA/TM—2002-211366 36
Model 3bb

Oblique Views

1. One-Point Statistics

2. Two-Point Statistics

1. 

Single Plane Views

Theta = 0°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

1. 

2. 

1. 

Model 3ab

Oblique Views

1. One-Point Statistics

2. Two-Point Statistics

1. 

Single Plane Views

Theta = 0°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

1. 

Theta = 5°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

2. 

Theta = 10°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

3. 

Theta = 15°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

4. 

Theta = 20°

1. One-Point Statistics

2. Two-Point Statistics

5. 

2. 

2. 

NASA/TM—2002-211366 37
3. Lengthscale Statistics

Theta = 25°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

6. 

Theta = 30°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

7. 

Model 3tb

Oblique Views

1. One-Point Statistics

2. Two-Point Statistics

1. 

Single Plane Views

Theta = 0°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

1. 

Theta = 5°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

2. 

Theta = 10°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

3. 

Theta = 15°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

4. 

Theta = 20°

1. One-Point Statistics

5. 

2. 

3. 

NASA/TM—2002-211366 38
2. Two-Point Statistics

3. Lengthscale Statistics

Theta = 25°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

6. 

Theta = 30°

1. One-Point Statistics

2. Two-Point Statistics

3. Lengthscale Statistics

7. 

NASA/TM—2002-211366 39
Figure 1.0.1.1 Model 3bb. Contour plots of data quality (#good out of 400). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 1.0.1.2 Model 3bb. Contour plots of time average axial velocity (m/s). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 40
Figure 1.0.1.3 Model 3bb. Contour plots of time average radial velocity (m/s). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 1.0.1.4 Model 3bb. Contour plots of time average Reynolds stress (m^2/s^2). Slices

taken at x = {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 41
Figure 1.0.1.5 Model 3bb. Contour plots of variance of axial velocity (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 1.0.1.6 Model 3bb. Contour plots of variance in radial velocity (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 42
Figure 1.0.1.7 Model 3bb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slices taken at

x = {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 1.0.1.8 Model 3bb. Contour plots of turbulent kinetic energy (m^2/s^2). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 43
Figure 1.0.1.9 Model 3bb. Contour plots of axial turbulence intensity. Slices taken at x = {0.047

0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 1.0.1.10 Model 3bb. Contour plots of radial turbulence intensity. Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 44
Figure 1.0.1.11 Model 3bb. Contour plots of turbulence intensity. Slices taken at x = {0.047

0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 1.0.1.12 Model 3bb. Contour plots of ratio of axial to radial turbulence. Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 45
Figure 1.0.2.1 Model 3bb. Contour plots of u(xref)u(x). Slices taken at radius = {0.00 0.03 0.06

0.09 0.12 0.15 0.18 0.21 0.24} meters.

NASA/TM—2002-211366 46
Figure 1.0.2.2 Model 3bb. Contour plots of v(xref)v(x). Slices taken at radius = {0.00 0.03 0.06

0.09 0.12 0.15 0.18 0.21 0.24} meters.

NASA/TM—2002-211366 47
Figure 1.1.1.1 Model 3bb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 0°.

Figure 1.1.1.2 Model 3bb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 0°.

Figure 1.1.1.3 Model 3bb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 0°.

Figure 1.1.1.4 Model 3bb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 0°.

Figure 1.1.1.5 Model 3bb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 48
Figure 1.1.1.6 Model 3bb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 1.1.1.7 Model 3bb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 1.1.1.8 Model 3bb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 1.1.1.9 Model 3bb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 49
Figure 1.1.1.10 Model 3bb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 0°.

Figure 1.1.1.11 Model 3bb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 0°.

Figure 1.1.1.12 Model 3bb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 50
Figure 1.1.2.1 Model 3bb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 51
Figure 1.1.2.2 Model 3bb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 52
Figure 1.1.2.3 Model 3bb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 53
Figure 1.1.2.4 Model 3bb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 54
Figure 1.1.3.1 Model 3bb. Contour plots of Luu(x). Slice taken at circumferential angle = 0°.

Figure 1.1.3.2 Model 3bb. Contour plots of Luu(y). Slice taken at circumferential angle = 0°.

Figure 1.1.3.3 Model 3bb. Contour plots of Lvv(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 55
Figure 1.1.3.6 Model 3bb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

0°.

Figure 1.1.3.4 Model 3bb. Contour plots of Lvv(y). Slice taken at circumferential angle = 0°.

Figure 1.1.3.5 Model 3bb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

0°.

NASA/TM—2002-211366 56
Figure 2.0.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 2.0.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 57
Figure 2.0.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 2.0.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slices

taken at x = {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 58
Figure 2.0.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 2.0.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 59
Figure 2.0.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slices taken at

x = {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 2.0.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 60
Figure 2.0.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slices taken at x = {0.047

0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 2.0.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 61
Figure 2.0.1.11 Model 3ab. Contour plots of turbulence intensity. Slices taken at x = {0.047

0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 2.0.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 62
Figure 2.0.2.1 Model 3ab. Contour plots of u(xref)u(x). Slices taken at radius = {0.00 0.03 0.06

0.09 0.12 0.15 0.18 0.21 0.24} meters.

NASA/TM—2002-211366 63
Figure 2.0.2.2 Model 3ab. Contour plots of v(xref)v(x). Slices taken at radius = {0.00 0.03 0.06

0.09 0.12 0.15 0.18 0.21 0.24} meters.

NASA/TM—2002-211366 64
Figure 2.1.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 0°.

Figure 2.1.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 0°.

Figure 2.1.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 0°.

Figure 2.1.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 0°.

Figure 2.1.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 65
Figure 2.1.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 2.1.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 2.1.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 2.1.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 66
Figure 2.1.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 0°.

Figure 2.1.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 0°.

Figure 2.1.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 67
Figure 2.1.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 68
Figure 2.1.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 69
Figure 2.1.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 70
Figure 2.1.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 71
Figure 2.1.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 0°.

Figure 2.1.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 0°.

Figure 2.1.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 72
Figure 2.1.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

0°.

Figure 2.1.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 0°.

Figure 2.1.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

0°.

NASA/TM—2002-211366 73
Figure 2.2.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 5°.

Figure 2.2.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 5°.

Figure 2.2.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 5°.

Figure 2.2.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 5°.

Figure 2.2.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 5°.

NASA/TM—2002-211366 74
Figure 2.2.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 5°.

Figure 2.2.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 5°.

Figure 2.2.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 5°.

Figure 2.2.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 5°.

NASA/TM—2002-211366 75
Figure 2.2.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 5°.

Figure 2.2.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 5°.

Figure 2.2.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 5°.

NASA/TM—2002-211366 76
Figure 2.2.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 77
Figure 2.2.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 78
Figure 2.2.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 79
Figure 2.2.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 80
Figure 2.2.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 5°.

Figure 2.2.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 5°.

Figure 2.2.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 81
Figure 2.2.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

5°.

Figure 2.2.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 5°.

Figure 2.2.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

5°.

NASA/TM—2002-211366 82
Figure 2.3.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 10°.

Figure 2.3.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 10°.

Figure 2.3.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 10°.

Figure 2.3.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 10°.

NASA/TM—2002-211366 83
Figure 2.3.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 10°.

Figure 2.3.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 10°.

Figure 2.3.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 10°.

Figure 2.3.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 10°.

NASA/TM—2002-211366 84
Figure 2.3.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 10°.

Figure 2.3.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 10°.

Figure 2.3.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 10°.

Figure 2.3.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 10°.

NASA/TM—2002-211366 85
Figure 2.3.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 86
Figure 2.3.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 87
Figure 2.3.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 88
Figure 2.3.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 89
Figure 2.3.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 10°.

Figure 2.3.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 10°.

Figure 2.3.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 90
Figure 2.3.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

10°.

Figure 2.3.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 10°.

Figure 2.3.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

10°.

NASA/TM—2002-211366 91
Figure 2.4.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 15°.

Figure 2.4.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 15°.

Figure 2.4.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 15°.

Figure 2.4.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 15°.

NASA/TM—2002-211366 92
Figure 2.4.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 15°.

Figure 2.4.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 15°.

Figure 2.4.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 15°.

Figure 2.4.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 15°.

NASA/TM—2002-211366 93
Figure 2.4.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 15°.

Figure 2.4.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 15°.

Figure 2.4.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 15°.

Figure 2.4.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 15°.

NASA/TM—2002-211366 94
Figure 2.4.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 95
Figure 2.4.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 96
Figure 2.4.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 97
Figure 2.4.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 98
Figure 2.4.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 15°.

Figure 2.4.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 15°.

Figure 2.4.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 99
Figure 2.4.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

15°.

Figure 2.4.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 15°.

Figure 2.4.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

15°.

NASA/TM—2002-211366 100
Figure 2.5.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 20°.

Figure 2.5.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 20°.

Figure 2.5.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 20°.

Figure 2.5.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 20°.

NASA/TM—2002-211366 101
Figure 2.5.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 20°.

Figure 2.5.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 20°.

Figure 2.5.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 20°.

Figure 2.5.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 20°.

NASA/TM—2002-211366 102
Figure 2.5.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 20°.

Figure 2.5.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 20°.

Figure 2.5.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 20°.

Figure 2.5.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 20°.

NASA/TM—2002-211366 103
Figure 2.5.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 104
Figure 2.5.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 105
Figure 2.5.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 106
Figure 2.5.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 107
Figure 2.5.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 20°.

Figure 2.5.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 20°.

Figure 2.5.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 108
Figure 2.5.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

20°.

Figure 2.5.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 20°.

Figure 2.5.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

20°.

NASA/TM—2002-211366 109
Figure 2.6.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 25°.

Figure 2.6.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 25°.

Figure 2.6.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 25°.

Figure 2.6.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 25°.

NASA/TM—2002-211366 110
Figure 2.6.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 25°.

Figure 2.6.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 25°.

Figure 2.6.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 25°.

Figure 2.6.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 25°.

NASA/TM—2002-211366 111
Figure 2.6.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 25°.

Figure 2.6.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 25°.

Figure 2.6.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 25°.

Figure 2.6.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 25°.

NASA/TM—2002-211366 112
Figure 2.6.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 113
Figure 2.6.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 114
Figure 2.6.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 115
Figure 2.6.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 116
Figure 2.6.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 25°.

Figure 2.6.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 25°.

Figure 2.6.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 117
Figure 2.6.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

25°.

Figure 2.6.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 25°.

Figure 2.6.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

25°.

NASA/TM—2002-211366 118
Figure 2.7.1.1 Model 3ab. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 30°.

Figure 2.7.1.2 Model 3ab. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 30°.

Figure 2.7.1.3 Model 3ab. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 30°.

Figure 2.7.1.4 Model 3ab. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 30°.

NASA/TM—2002-211366 119
Figure 2.7.1.5 Model 3ab. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 30°.

Figure 2.7.1.6 Model 3ab. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 30°.

Figure 2.7.1.7 Model 3ab. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 30°.

Figure 2.7.1.8 Model 3ab. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 30°.

NASA/TM—2002-211366 120
Figure 2.7.1.10 Model 3ab. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 30°.

Figure 2.7.1.11 Model 3ab. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 30°.

Figure 2.7.1.12 Model 3ab. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 30°.

Figure 2.7.1.9 Model 3ab. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 30°.

NASA/TM—2002-211366 121
Figure 2.7.2.1 Model 3ab. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 122
Figure 2.7.2.2 Model 3ab. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 123
Figure 2.7.2.3 Model 3ab. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 124
Figure 2.7.2.4 Model 3ab. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 125
Figure 2.7.3.1 Model 3ab. Contour plots of Luu(x). Slice taken at circumferential angle = 30°.

Figure 2.7.3.2 Model 3ab. Contour plots of Luu(y). Slice taken at circumferential angle = 30°.

Figure 2.7.3.3 Model 3ab. Contour plots of Lvv(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 126
Figure 2.7.3.6 Model 3ab. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

30°.

NASA/TM—2002-211366 127

Figure 2.7.3.4 Model 3ab. Contour plots of Lvv(y). Slice taken at circumferential angle = 30°.

Figure 2.7.3.5 Model 3ab. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

30°.
Figure 3.0.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 3.0.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 128
Figure 3.0.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 3.0.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slices taken

at x = {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 129
Figure 3.0.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 3.0.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 130
Figure 3.0.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slices taken at x

= {0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 3.0.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 131
Figure 3.0.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slices taken at x = {0.047

0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 3.0.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slices taken at x = {0.047

0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 132
Figure 3.0.1.11 Model 3tb. Contour plots of turbulence intensity. Slices taken at x = {0.047 0.132

0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

Figure 3.0.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slices taken at x =

{0.047 0.132 0.199 0.267 0.334 0.401 0.468 0.535 0.603 0.670 0.737} meters.

NASA/TM—2002-211366 133
Figure 3.0.2.1 Model 3tb. Contour plots of u(xref)u(x). Slices taken at radius = {0.00 0.03 0.06

0.09 0.12 0.15 0.18 0.21 0.24} meters.

NASA/TM—2002-211366 134
Figure 3.0.2.2 Model 3tb. Contour plots of v(xref)v(x). Slices taken at radius = {0.00 0.03 0.06

0.09 0.12 0.15 0.18 0.21 0.24} meters.

NASA/TM—2002-211366 135
Figure 3.1.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 0°.

Figure 3.1.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 0°.

Figure 3.1.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 0°.

Figure 3.1.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 0°.

NASA/TM—2002-211366 136
Figure 3.1.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 3.1.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 3.1.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 0°.

Figure 3.1.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 137
Figure 3.1.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 0°.

Figure 3.1.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 0°.

Figure 3.1.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 0°.

Figure 3.1.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 0°.

NASA/TM—2002-211366 138
Figure 3.1.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 139
Figure 3.1.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 140
Figure 3.1.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 141
Figure 3.1.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 142
Figure 3.1.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 0°.

Figure 3.1.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 0°.

Figure 3.1.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 143
Figure 3.1.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

0°.

Figure 3.1.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

0°.

Figure 3.1.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 0°.

NASA/TM—2002-211366 144
Figure 3.2.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 5°.

Figure 3.2.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 5°.

Figure 3.2.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 5°.

Figure 3.2.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 5°.

NASA/TM—2002-211366 145
Figure 3.2.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 5°.

Figure 3.2.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 5°.

Figure 3.2.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 5°.

Figure 3.2.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 5°.

NASA/TM—2002-211366 146
Figure 3.2.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 5°.

Figure 3.2.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 5°.

Figure 3.2.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 5°.

Figure 3.2.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 5°.

NASA/TM—2002-211366 147
Figure 3.2.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 148
Figure 3.2.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 149
Figure 3.2.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 150
Figure 3.2.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 151
Figure 3.2.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 5°.

Figure 3.2.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 5°.

Figure 3.2.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 5°.

NASA/TM—2002-211366 152
Figure 3.2.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

5°.

Figure 3.2.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 5°.

Figure 3.2.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

5°.

NASA/TM—2002-211366 153
Figure 3.3.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 10°.

Figure 3.3.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 10°.

Figure 3.3.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 10°.

Figure 3.3.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 10°.

NASA/TM—2002-211366 154
Figure 3.3.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 10°.

Figure 3.3.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 10°.

Figure 3.3.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 10°.

Figure 3.3.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 10°.

NASA/TM—2002-211366 155
Figure 3.3.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 10°.

Figure 3.3.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 10°.

Figure 3.3.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 10°.

Figure 3.3.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 10°.

NASA/TM—2002-211366 156
Figure 3.3.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 157
Figure 3.3.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 158
Figure 3.3.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 159
Figure 3.3.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 160
Figure 3.3.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 10°.

Figure 3.3.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 10°.

Figure 3.3.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 10°.

NASA/TM—2002-211366 161
Figure 3.3.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

10°.

Figure 3.3.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 10°.

Figure 3.3.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

10°.

NASA/TM—2002-211366 162
Figure 3.4.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 15°.

Figure 3.4.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 15°.

Figure 3.4.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 15°.

Figure 3.4.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 15°.

NASA/TM—2002-211366 163
Figure 3.4.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 15°.

Figure 3.4.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 15°.

Figure 3.4.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 15°.

Figure 3.4.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 15°.

NASA/TM—2002-211366 164
Figure 3.4.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 15°.

Figure 3.4.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 15°.

Figure 3.4.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 15°.

Figure 3.4.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 15°.

NASA/TM—2002-211366 165
Figure 3.4.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 166
Figure 3.4.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 167
Figure 3.4.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 168
Figure 3.4.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 169
Figure 3.4.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 15°.

Figure 3.4.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 15°.

Figure 3.4.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 15°.

NASA/TM—2002-211366 170
Figure 3.4.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

15°.

Figure 3.4.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 15°.

Figure 3.4.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

15°.

NASA/TM—2002-211366 171
Figure 3.5.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 20°.

Figure 3.5.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 20°.

Figure 3.5.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 20°.

Figure 3.5.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 20°.

NASA/TM—2002-211366 172
Figure 3.5.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 20°.

Figure 3.5.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 20°.

Figure 3.5.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 20°.

Figure 3.5.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 20°.

NASA/TM—2002-211366 173
Figure 3.5.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 20°.

Figure 3.5.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 20°.

Figure 3.5.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 20°.

Figure 3.5.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 20°.

NASA/TM—2002-211366 174
Figure 3.5.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 175
Figure 3.5.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 176
Figure 3.5.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 177
Figure 3.5.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 178
Figure 3.5.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 20°.

Figure 3.5.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 20°.

Figure 3.5.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 20°.

NASA/TM—2002-211366 179
Figure 3.5.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

20°.

Figure 3.5.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 20°.

Figure 3.5.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

20°.

NASA/TM—2002-211366 180
Figure 3.6.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 25°.

Figure 3.6.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 25°.

Figure 3.6.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 25°.

Figure 3.6.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 25°.

NASA/TM—2002-211366 181
Figure 3.6.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 25°.

Figure 3.6.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 25°.

Figure 3.6.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 25°.

Figure 3.6.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 25°.

NASA/TM—2002-211366 182
Figure 3.6.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 25°.

Figure 3.6.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 25°.

Figure 3.6.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 25°.

Figure 3.6.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 25°.

NASA/TM—2002-211366 183
Figure 3.6.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 184
Figure 3.6.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 185
Figure 3.6.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 186
Figure 3.6.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 187
Figure 3.6.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 25°.

Figure 3.6.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 25°.

Figure 3.6.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 25°.

NASA/TM—2002-211366 188
Figure 3.6.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

25°.

Figure 3.6.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 25°.

Figure 3.6.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

25°.

NASA/TM—2002-211366 189
Figure 3.7.1.1 Model 3tb. Contour plots of data quality (#good out of 400). Slice taken at

circumferential angle = 30°.

Figure 3.7.1.2 Model 3tb. Contour plots of time average axial velocity (m/s). Slice taken at

circumferential angle = 30°.

Figure 3.7.1.3 Model 3tb. Contour plots of time average radial velocity (m/s). Slice taken at

circumferential angle = 30°.

Figure 3.7.1.4 Model 3tb. Contour plots of time average Reynolds stress (m^2/s^2). Slice taken

at circumferential angle = 30°.

NASA/TM—2002-211366 190
Figure 3.7.1.5 Model 3tb. Contour plots of variance of axial velocity (m^2/s^2). Slice taken at

circumferential angle = 30°.

Figure 3.7.1.6 Model 3tb. Contour plots of variance in radial velocity (m^2/s^2). Slice taken at

circumferential angle = 30°.

Figure 3.7.1.7 Model 3tb. Contour plots of unsteady Reynolds stress (m^2/s^2). Slice taken at

circumferential angle = 30°.

Figure 3.7.1.8 Model 3tb. Contour plots of turbulent kinetic energy (m^2/s^2). Slice taken at

circumferential angle = 30°.

NASA/TM—2002-211366 191
Figure 3.7.1.10 Model 3tb. Contour plots of radial turbulence intensity. Slice taken at

circumferential angle = 30°.

Figure 3.7.1.11 Model 3tb. Contour plots of turbulence intensity. Slice taken at circumferential

angle = 30°.

Figure 3.7.1.12 Model 3tb. Contour plots of ratio of axial to radial turbulence. Slice taken at

circumferential angle = 30°.

Figure 3.7.1.9 Model 3tb. Contour plots of axial turbulence intensity. Slice taken at

circumferential angle = 30°.

NASA/TM—2002-211366 192
Figure 3.7.2.1 Model 3tb. Contour plots of u(xref)u(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 193
Figure 3.7.2.2 Model 3tb. Contour plots of v(xref)v(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 194
Figure 3.7.2.3 Model 3tb. Contour plots of u(xref)v(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 195
Figure 3.7.2.4 Model 3tb. Contour plots of v(xref)u(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 196
Figure 3.7.3.1 Model 3tb. Contour plots of Luu(x). Slice taken at circumferential angle = 30°.

Figure 3.7.3.2 Model 3tb. Contour plots of Luu(y). Slice taken at circumferential angle = 30°.

Figure 3.7.3.3 Model 3tb. Contour plots of Lvv(x). Slice taken at circumferential angle = 30°.

NASA/TM—2002-211366 197
Figure 3.7.3.6 Model 3tb. Contour plots of Lvv(y)/Luu(y). Slice taken at circumferential angle =

30°.

Figure 3.7.3.4 Model 3tb. Contour plots of Lvv(y). Slice taken at circumferential angle = 30°.

Figure 3.7.3.5 Model 3tb. Contour plots of Luu(x)/Lvv(x). Slice taken at circumferential angle =

30°.

NASA/TM—2002-211366 198
 14 Appendix C: Data files

Data files are provided in electronic versions of this document. They are files of the turbulence statistics

calculated and plotted in Appendix B. The data files are in ASCII formatted ‘plot3D’ function format and

located in the folder entitled 'p3d_data'.

NASA/TM—2002-211366 199
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205

Measurements of Turbulent Flow Field in Separate Flow Nozzles With Enhanced

Mixing Devices—Test Report

James Bridges

Particle image velocimetry; Unsteady flow; Turbofan engines; Turbulent flow;

Nozzle flow; Flow measurement; Noise reduction; Jet aircraft noise; Turbulence

Unclassified -Unlimited

Subject Categories: 07, 09, and 34 Distribution: Nonstandard

Responsible person, James Bridges, organization code 5940, 216–433–2693.

As part of the Advanced Subsonic Technology Program, a series of experiments was conducted at NASA Glenn Research Center on the

effect of mixing enhancement devices on the aeroacoustic performance of separate flow nozzles. Initial acoustic evaluations of the

devices showed that they reduced jet noise significantly, while creating very little thrust loss. The explanation for the improvement

required that turbulence measurements, namely single point mean and RMS statistics and two-point spatial correlations, be made to

determine the change in the turbulence caused by the mixing enhancement devices that lead to the noise reduction, These measurements

were made in the summer of 2000 in a test program called Separate Nozzle Flow Test 2000 (SFNT2K) supported by the Aeropropulsion

Research Program at NASA Glenn Research Center. Given the hot high-speed flows representative of a contemporary bypass ratio 5

turbofan engine, unsteady flow field measurements required the use of an optical measurement method. To achieve the spatial correlations, the Particle Image Velocimetry technique was employed, acquiring high-density velocity maps of the flows from which the

required statistics could be derived. This was the first successful use of this technique for such flows, and shows the utility of this

technique for future experimental programs. The extensive statistics obtained were likewise unique and give great insight into the

turbulence which produces noise and how the turbulence can he modified to reduce jet noise. This report documents the test facilities

and procedures used to obtain the turbulence data. It also contains an indexed overview of the results, both in graphical and numerical

formats.