NASA/TM–2008–215103

Effect of Protuberance Shape and

Orientation on Space Shuttle Orbiter

Boundary-Layer Transition

Rudolph A. King, Scott A. Berry, Michael A. Kegerise

Langley Research Center, Hampton, Virginia

February 2008
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NASA/TM–2008–215103

Effect of Protuberance Shape and

Orientation on Space Shuttle Orbiter

Boundary-Layer Transition

Rudolph A. King, Scott A. Berry, Michael A. Kegerise

Langley Research Center, Hampton, Virginia

National Aeronautics and

Space Administration

Langley Research Center

Hampton, Virginia 23681-2199

February 2008
Acknowledgments

This wind-tunnel test would not have been possible without the support and dedication of many

individuals: Michael Powers and Mark Griffith for ceramic model fabrication; Pete Veneris for fiducial-mark

placement; Walter Wade, Kevin Bonilla and John Hopkins for manufacturing the boundary-layer trips;

Gary Wainwright and Louis Simmons for manufacturing the hole template and drilling the holes for trip

placement; and Grace Gleason, Rhonda Mills, Harry ”Buddy” Stotler and Teck-Seng Kwa for 20-Inch

Mach 6 Air Tunnel support and data acquisition. The authors are grateful for their contributions.

The use of trademarks or names of manufacturers in this report is for accurate reporting and does not

constitute an offical endorsement, either expressed or implied, of such products or manufacturers by the

National Aeronautics and Space Administration.

Available from:

NASA Center for AeroSpace Information (CASI) National Technical Information Service (NTIS)

7115 Standard Drive 5285 Port Royal Road

Hanover, MD 21076–1320 Springfield, VA 22161–2171

(301) 621–0390 (703) 605–6000
Abstract

This document describes an experimental study conducted to examine the effects of protuberances on hypersonic boundary-layer transition. The experiment was conducted in the

Langley 20-Inch Mach 6 Tunnel on a series of 0.9%-scale Shuttle Orbiter models. The data

were acquired to complement the existing ground-based boundary-layer transition database

that was used to develop Version 1.0 of the boundary-layer transition RTF (return-to-flight)

tool. The existing ground-based data were all acquired on 0.75%-scale Orbiter models using

diamond-shaped (“pizza-box”) trips. The larger model scale facilitated in manufacturing

higher fidelity protuberances. The end use of this experimental database will be to develop

a technical basis (in the form of a boundary-layer transition correlation) to assess representative protrusion shapes, e.g., gap fillers and protrusions resulting from possible tile repair

concepts. The primary objective of this study is to investigate the effects of protuberancetrip location and geometry on Shuttle Orbiter boundary-layer transition. Secondary goals

are to assess the effects of gap-filler orientation and other protrusion shapes on boundarylayer transition. Global heat-transfer images using phosphor thermography of the Orbiter

windward surface and the corresponding streamwise and spanwise heating distributions were

used to infer the state of the boundary layer, i.e., laminar, transitional, or turbulent.

1
Contents

List of Tables 3

List of Figures 4

1 Introduction 7

2 Experimental Methods 8

2.1 Test Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2 Test Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3 Test Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.4 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.5 Test Matrix and Tunnel Conditions . . . . . . . . . . . . . . . . . . . . . . . . 13

3 Results and Discussion 13

3.1 Untripped Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2 Tripped Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4 Summary 17

References 19

2
List of Tables

1 Plug locations for the tripped model configurations. . . . . . . . . . . . . . . 21

2 Fiducial locations on all the final models. . . . . . . . . . . . . . . . . . . . . 21

3 Protuberance dimensions and quantities requested to be manufactured. Note

that the trip heights, k, in the table are the designed values, not the as-built

heights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4 Proposed test plan and test conditions for models with protuberances (baseline configuration tests not included). . . . . . . . . . . . . . . . . . . . . . . . 22

5 Test 6922 final run log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5 Test 6922 final run log – (Cont). . . . . . . . . . . . . . . . . . . . . . . . . . 24

5 Test 6922 final run log – (Cont). . . . . . . . . . . . . . . . . . . . . . . . . . 25

5 Test 6922 final run log – (Cont). . . . . . . . . . . . . . . . . . . . . . . . . . 26

6 Final Test 6922 matrix and BLT Tool v.1 flow parameters based on LATCH

solutions for models with protuberances (baseline configuration test results

not included). The nominal Mach number is M = 6 for all test conditions. . . 27

3
List of Figures

1 Photograph of a 0.9%-scale Orbiter model installed in the LaRC 20-Inch Mach

6 Air Tunnel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2 Sketch of a 0.9%-scale Orbiter model installed in the LaRC 20-Inch Mach 6

Air Tunnel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3 Windward surface sketch of the 7 models used for Test 6922. Holes to accommodate metal dowels are indicated by the filled blue circles. . . . . . . . . 29

4 Schematic of trip-dowel assemblies used as protuberances. . . . . . . . . . . . 30

5 Photograph of four typical trip-dowel assemblies used as protuberances are

shown above to demonstrate the scale of the trips. The trip-dowel assemblies

shown from left to right are a pizza-box trip, a rounded pizza-box trip, a

hemisphere trip, and a fence trip. . . . . . . . . . . . . . . . . . . . . . . . . . 31

6 Schematic depicting a blank dowel inserted into a cast ceramic model to

match OML of surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

7 Illustration of phosphor thermography acquisition system. . . . . . . . . . . . 33

8 Photographic image of model 1 installed in the 20-Inch Mach 6 Air Tunnel. . 34

9 Global aeroheating images for baseline model 1. . . . . . . . . . . . . . . . . . 35

10 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for baseline model 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

11 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for baseline model 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

12 Sketch and close-up image of model 2 with a blank dowel installed. . . . . . . 37

13 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 2 with a blank dowel and baseline model 1. . . . . . . . . . . . . . 38

14 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 2 with a blank dowel and baseline model 1. . . . . . . . . . . . . . 38

15 Close-up image of model 2 with configuration 1. . . . . . . . . . . . . . . . . . 39

16 Global aeroheating images for model 2 with configuration 1. . . . . . . . . . . 40

17 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 2 with configuration 1. . . . . . . . . . . . . . . . . . . . . . . . . . 41

18 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 2 with configuration 1. . . . . . . . . . . . . . . . . . . . . . . . . . 41

19 Close-up image of model 2 with configuration 2. Clockwise rotation of fence

relative to model centerline is denoted as positive angle. . . . . . . . . . . . . 42

20 Global aeroheating images for model 2 with configuration 2. . . . . . . . . . . 43

21 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 2 with configuration 2. . . . . . . . . . . . . . . . . . . . . . . . . . 44

22 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 2 with configuration 2. . . . . . . . . . . . . . . . . . . . . . . . . . 44

23 Sketch and close-up image of model 3 with three blank dowels installed. . . . 45

24 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with three blank dowels and baseline model 1. . . . . . . . . . . . 46

25 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with three blank dowels and baseline model 1. . . . . . . . . . . . 46

26 Close-up image of model 3 with configuration 5. Clockwise rotation of fence

relative to model centerline is denoted as positive angle. . . . . . . . . . . . . 47

27 Global aeroheating images for model 3 with configuration 5. . . . . . . . . . . 48

28 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with configuration 5. . . . . . . . . . . . . . . . . . . . . . . . . . 49

29 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with configuration 5. . . . . . . . . . . . . . . . . . . . . . . . . . 49

4
30 Close-up image of model 3 with configuration 5A. Clockwise rotation of fence

relative to model centerline is denoted as positive angle. . . . . . . . . . . . . 50

31 Global aeroheating images for model 3 with configuration 5A. . . . . . . . . . 51

32 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with configuration 5A. . . . . . . . . . . . . . . . . . . . . . . . . 52

33 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with configuration 5A. . . . . . . . . . . . . . . . . . . . . . . . . 52

34 Close-up image of model 3 with configuration 5B. Clockwise rotation of fence

relative to model centerline is denoted as positive angle. . . . . . . . . . . . . 53

35 Global aeroheating images for model 3 with configuration 5B. . . . . . . . . . 54

36 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with configuration 5B. . . . . . . . . . . . . . . . . . . . . . . . . 55

37 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with configuration 5B. . . . . . . . . . . . . . . . . . . . . . . . . 55

38 Close-up image of model 4 with three blank dowels installed. . . . . . . . . . 56

39 Global aeroheating images for model 4 with three blank dowels. . . . . . . . . 57

40 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with three blank dowels. . . . . . . . . . . . . . . . . . . . . . . . 58

41 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.8

for model 4 with three blank dowels . . . . . . . . . . . . . . . . . . . . . . . 58

42 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with three blank dowels and baseline model 1. . . . . . . . . . . . 59

43 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.8

for model 4 with three blank dowels and baseline model 1. . . . . . . . . . . . 59

44 Close-up image of model 4 with configuration 6A. Clockwise rotation of fence

relative to model centerline is denoted as positive angle. . . . . . . . . . . . . 60

45 Global aeroheating images for model 4 with configuration 6A. . . . . . . . . . 61

46 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with configuration 6A. . . . . . . . . . . . . . . . . . . . . . . . . 62

47 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 4 with configuration 6A. . . . . . . . . . . . . . . . . . . . . . . . . 62

48 Close-up image of model 4 with configuration 6B. Diagonal of PB trip is at

45◦from model centerline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

49 Global aeroheating images for model 4 with configuration 6B. . . . . . . . . . 64

50 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with configuration 6B. . . . . . . . . . . . . . . . . . . . . . . . . 65

51 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 4 with configuration 6B. . . . . . . . . . . . . . . . . . . . . . . . . 65

52 Close-up image of model 4 with configuration 6C. Diagonal of PB trip is

approximately −22.5

◦

from model centerline. . . . . . . . . . . . . . . . . . . 66

53 Global aeroheating images for model 4 with configuration 6C. . . . . . . . . . 67

54 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with configuration 6C. . . . . . . . . . . . . . . . . . . . . . . . . 68

55 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 4 with configuration 6C. . . . . . . . . . . . . . . . . . . . . . . . . 68

56 Close-up image of model 6 with a blank dowel installed. . . . . . . . . . . . . 69

57 Global aeroheating images for model 6 with a blank dowel. . . . . . . . . . . 70

58 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with a blank dowel. . . . . . . . . . . . . . . . . . . . . . . . . . . 71

59 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with a blank dowel. . . . . . . . . . . . . . . . . . . . . . . . . . . 71

5
60 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with a blank dowel and baseline model 1. . . . . . . . . . . . . . 72

61 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.8

for model 6 with a blank dowel and baseline model 1. . . . . . . . . . . . . . 72

62 Close-up image of model 6 with configuration 12. . . . . . . . . . . . . . . . . 73

63 Global aeroheating images for model 6 with configuration 12. . . . . . . . . . 74

64 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with configuration 12. . . . . . . . . . . . . . . . . . . . . . . . . 75

65 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with configuration 12. . . . . . . . . . . . . . . . . . . . . . . . . 75

66 Close-up image of model 6 with configuration 12B. . . . . . . . . . . . . . . . 76

67 Global aeroheating images for model 6 with configuration 12B. . . . . . . . . 77

68 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with configuration 12B. . . . . . . . . . . . . . . . . . . . . . . . 78

69 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with configuration 12B. . . . . . . . . . . . . . . . . . . . . . . . 78

70 Close-up image of model 6 with configuration 12A. . . . . . . . . . . . . . . . 79

71 Global aeroheating images for model 6 with configuration 12A. . . . . . . . . 80

72 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with configuration 12A. . . . . . . . . . . . . . . . . . . . . . . . 81

73 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with configuration 12A. . . . . . . . . . . . . . . . . . . . . . . . 81

74 Photographic image of model 7 installed in the 20-Inch Mach 6 Air Tunnel. . 82

75 Global aeroheating images for baseline model 7. . . . . . . . . . . . . . . . . . 83

76 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for baseline model 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

77 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for baseline model 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

78 Global aeroheating images for baseline model 7 and baseline model 1. . . . . 85

79 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for baseline model 7 and baseline model 1. . . . . . . . . . . . . . . . . . . . . 86

80 Sketch and close-up image of model 5 with three blank dowels installed. . . . 87

81 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 5 with three blank dowels and baseline model 1. . . . . . . . . . . . 88

82 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 5 with three blank dowels and baseline model 1. . . . . . . . . . . . 88

83 Close-up image of model 5 with configuration 8. . . . . . . . . . . . . . . . . . 89

84 Global aeroheating images for model 5 with configuration 8. . . . . . . . . . . 90

85 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 5 with configuration 8. . . . . . . . . . . . . . . . . . . . . . . . . . 91

86 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 5 with configuration 8. . . . . . . . . . . . . . . . . . . . . . . . . . 91

87 Close-up image of model 5 with configuration 8A. . . . . . . . . . . . . . . . . 92

88 Global aeroheating images for model 5 with configuration 8A. . . . . . . . . . 93

89 Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 5 with configuration 8A. . . . . . . . . . . . . . . . . . . . . . . . . 94

90 Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 5 with configuration 8A. . . . . . . . . . . . . . . . . . . . . . . . . 94

91 Comparison of existing Mach 6 data and newly acquired TEI data in the

parameter space of the BLT Tool v.1. . . . . . . . . . . . . . . . . . . . . . . 95

6
1 Introduction

The Entry Aeroheating Working Group led by NASA Johnson Space Center was created as

a result of the Columbia Accident Investigation Board’s (CAIB) final report [1] to address

the health of the Orbiter’s thermal protection system (TPS) prior to reentry. Part of the

charter of this working group (see Ref. [2] for details) is to provide real-time support to the

Damage Assessment Team during each Shuttle mission subsequent to STS-107 (STS - Space

Transportation System). Damage to the ceramic tiles that cover a majority of the Shuttle

windward surface is typically in the form of cavities resulting from debris impact during

launch, but can also comprise of protruding gap fillers from between the tiles. Depending

on the size and location of the resulting cavity or protrusion, the localized change in the

outer mold line (OML) may destabilize the windward surface boundary layer and lead to

premature boundary-layer transition during reentry. The boundary-layer transition (BLT)

tool, which is one of the suite of engineering tools developed by the working group, is used

in a rapid-turnaround environment to assess if and when these damage sites can cause early

transition on the windward surface. At the time of this study, the version of the BLT Tool

approved by the Shuttle Program was Version 1.0 [3–5]. This tool requires size, location

and geometry (i.e., cavity versus protuberance) of the damage/repair sites obtained from

on-orbit inspection to infer the expected time within the flight trajectory of boundary-layer

transition onset relative to entry interface. Early transition times (i.e., occurring at high

reentry Mach numbers) can lead to excessive thermal loads on the TPS and can ultimately

affect the safety margins of the vehicle.

The BLT Tool (Version 1.0) is based on correlations of identified thresholds for boundarylayer transition from discrete elements that simulate TPS damage/repair on the Orbiter.

That correlation methodology was established through a series of hypersonic wind-tunnel

experiments on scaled Shuttle models with simulated TPS damage/repair on the windward

surface [6, 7] and limited Orbiter flight data (recently reexamined flight data presented

in Ref. [8]). The focus of this study is to examine TPS damage in the form of raised

protuberances on the windward surface of the Orbiter. These protuberances are in the form

of gap fillers, raised tiles and potential tile repair concepts. The experimental wind-tunnel

database developed by Liechty et al. [6] was acquired on 0.75%-scaled Orbiter models with

protuberances in the form of diamond-shaped (“pizza-box”) trips. The data were obtained

in NASA Langley Research Center (LaRC) Aerothermodynamic Laboratory (LAL) which

consists of three hypersonic wind tunnels [9]. The three tunnels are the 20-Inch Mach 6

Air Tunnel, the 20-Inch Mach 6 CF4 Tunnel, and the 31-Inch Mach 10 Air Tunnel. The

test parametrics included angle-of-attack of 30 and 40 degrees, side-slip angle of 0 degrees,

freestream unit Reynolds numbers from 2 × 104to 7.3 × 106ft−1, wall-to-edge temperature

ratios of 0.4 to 0.8, and normal shock density ratios of approximately 5 (for Mach 6 and 10

air) and 12 (for Mach 6 CF4). Global heat-transfer images using phosphor thermography

of the Orbiter windward surface and the corresponding centerline and spanwise heating

distributions were used to infer the state of the boundary layer (laminar, transitional, or

turbulent). Transition onset (incipient1) values identified from that database, along with

predicted boundary-layer edge parameters, were used to formulate protuberance-induced

transition correlations for Version 1.0 of the BLT Tool [3–5].

This reports documents a wind-tunnel experiment conducted as part of a technical expert

investigation (TEI) study. TEI funding was allocated to the BLT team as a discretionary

resource to support potential studies that the team deemed important with concurrence

from the working group. The BLT team decided to use the resources to support ten days of

testing in the 20-Inch Mach 6 Air Tunnel for a protuberance-induced transition study, herein

1

Incipient transition is defined as the first appearance of transition on the Orbiter downstream of the

trip. When transition first occurs immediately downstream of the trip location, it is referred to effective

transition which is not the subject of this document.

7
referred to as the TEI study. The measurements were acquired on 0.9%-scale Orbiter models

at a nominal angle-of-attack of 40◦. The larger model scale (0.9% versus 0.75%) facilitated

in improved manufacturing capabilities of the protuberances. The current database expands

the existing Mach 6 database by acquiring data for other representative protuberance shapes

(e.g., gap fillers and shapes resulting from tile repair concepts) and for protuberances at aft

locations on the Orbiter. The primary objective of this study is to investigate the effects of

protuberance-trip geometry and location on Shuttle Orbiter boundary-layer transition. The

geometry sensitivity was done by simulating protuberance shapes that are representative

of those realized in flight. This addresses the outstanding question as to whether on not

protuberance shape (e.g., pizza box versus gap filler) has a first-order effect on incipient

transition. The location sensitivity is twofold. Namely, the existing database is limited to

protuberances located at x/Lref ≤ 0.7 and all outboard trip locations are confined to the

attachment-line region. The exception to these locations is limited data measured in the

20-Inch Mach 6 Air Tunnel during STS-121 mission support that were acquired on 0.75%-

scale models at a nominal angle-of-attack of 40◦[10]. Data are acquire in this TEI study

for x/Lref > 0.7 and at outboard locations inboard of the shock interaction region. The

secondary objective is to assess the effect of gap-filler orientation on the Orbiter boundarylayer transition. This newly acquired data will be used to help corroborate recently measured

MH-13 data [11] obtained in the Calspan-University of Buffalo Research Center (CUBRC)

LENS-I Shock Tunnel [12] on a 1.8%-scale Orbiter model and for the development of Version

2 of the BLT Tool.

2 Experimental Methods

2.1 Test Facility

The experimental study was performed in the NASA Langley Research Center 20-Inch Mach

6 Air Tunnel. The 20-Inch Mach 6 Air Tunnel is a blowdown facility in which heated, dried,

and filtered air is used as the test gas. The tunnel has a two-dimensional, contoured nozzle

that opens into a 20.5-inch by 20-inch test section. The tunnel is equipped with a bottommounted injection system that can transfer the model from the sheltered model box to the

tunnel centerline in less than 0.5 seconds. Run times on the order of 15 minutes are possible,

although for the current aeroheating study run times of only a few seconds are required.

The nominal reservoir conditions of the facility are stagnation pressures of 30 to 500 psi with

stagnation temperatures of 760 to 1000 ◦R, that very nearly produces perfect gas (γ = 1.4)

freestream flows with Mach numbers between 5.8 and 6.1 and unit Reynolds numbers of

0.5 × 106to 7.3 × 106ft−1. An image of an Orbiter model installed in the sheltered model

box of the facility is shown in Fig. 1. Recent calibration measurements in this facility [13]

indicate that the test-core diameter is at least 10 inches and can be as large as 14 inches

depending on the flow conditions. A schematic of a 0.9%-scale model in a 10-inch diameter

flow core of the facility is shown in Fig. 2, thus illustrating that the model fits in the uniform

flow core.

2.2 Test Models

The test models for this study, see Fig. 1, are cast ceramic Shuttle Orbiter models (Lref ≈

11.5 inches long from nose to body-flap hinge) manufactured with a standard construction

technique. An epoxy mold constructed from a 0.9%-scale stereo-lithography pattern of the

Shuttle 2002 CAD geometry was used to fabricate the models. (See Bibb [14] for more

details on the Shuttle 2002 CAD geometry.) Specifically, wax patterns created from the

mold were used to cast each individual Orbiter model using a patented silica ceramic slip

casting technique. The cast shells were then back-filled with a hydraulically setting silica

8
ceramic for strength and support of the base mounted cylindrical sting. Small ink-based

identification marks (i.e., fiducial marks) were then placed on the model surface to locate the

placement of the metallic dowels with attached protuberances and to assist in the alignment

of the model in the tunnel. The larger scale models and metal inserts were required in

order to more accurately reproduce the small-scale gap-filler trips. Finally, the models were

coated with a mixture of phosphors suspended in a silica-based colloidal binder. Buck et

al. [15] gives further details on the construction of the ceramic Orbiter models.

Seven basic model configurations were built: two baseline models (smooth OML models

with no holes for trips but intended to have different levels of phosphor coating distributed

roughness) and five with holes drilled perpendicular to the surface at distinct locations, as

shown in Fig. 3. Models 1 and 7 are the baseline models. Model 1 has a surface roughness

consistent with the other models. Hand working the model surface with soft-textured wipes

is the process typically used to remove the loose phosphor particles on the surface during

coating process. It is done by applying a reasonable amount of pressure between the wipe

and model surface without removing most of the phosphor coating. A final coat of binder

is applied to the model surface before testing. Model 7 was processed somewhat differently.

The loose phosphor particles were not removed from the model surface. A final coat of the

binder was applied to the model surface in preparation for testing. The surface of model 7

was hand worked slightly in the tunnel after the first run with this model to remove some of

the larger particles that prematurely tripped the flow. The model surface was hand worked

with a wipe by applying a few stokes so that some of the phosphor coating was lost. A

folded paper was then used to lightly brush the windward surface of the model to remove

any loose particles. Surface roughness measurements were acquired on both models after

the completion of the test using surface profilometry, a Taylor-Hobson Form Talysurf-120L.

Two measurements were obtained on the symmetry plane at x/Lref ≈ 0.2 and 0.7 and

one on each wing at (x/Lref , y/Lref ) ≈ (0.85, ±0.25) for both models. Note that the axial

distance from the nosetip is represented by x and the spanwise distance from the centerline

(CL) symmetry plane is y. The mean values of the four roughness averages, Ra, for model

1 and model 7 are Ra = 177 μ-in. (or root-mean-square roughness, Rq = 220 μ-in.) and

Ra = 281 μ-in. (Rq = 365 μ-in.), respectively. Before applying the phosphor coating on

models 2 - 6, holes were drilled normal to the model sufaces as indicated in Fig. 3. The

center locations of the precision drilled holes are given in Table 1. Fiducial marks were

placed at the location of the desired hole centers for models 2 - 6. A glove-like template

was fabricated using a stereo-lithography pattern from the Shuttle CAD geometry. This

fixture served as a setup guide for the drill press to insure that the holes were all normal to

the local model surface. After drilling the required hole(s) in each model, the models were

coated with the mixture of phosphors suspended in the binder. Final fiducial marks were

placed on all the models for alignment purposes and mapping of the thermography images

(locations identified in Table 2).

Fig. 4 shows the four basic trip-dowel insert configurations that were built along with

pertinent dimensions. All the trip configurations consisted of an external dowel (simply

referred to herein as dowel) in conjunction with either shim stock or an interior dowel. The

dowel assemblies, which are placed into the drilled holes within the ceramic, were cut from

precision drill rods. The bottom end of each dowel was bevelled for easy placement into the

models and the top end ground flat. For the dowels with slots, electrical discharge machining

(EDM) was used to generate the slots. The shim stock pieces, which were used to simulate

the protuberances, were cut using EDM or laser ablation depending on the thickness of

the shim stock. The “pizza-box” (PB) trips represent the previous database that utilized

adhesively backed Teflon trips on 0.75%-scale models [6]. The pizza-box trips for the 0.9%-

scaled models were sized at 0.06000 by 0.06000 as opposed to the 0.05000 by 0.05000 size used for

the 0.75%-scale models. The “rounded pizza-box” (RPB) trip was selected to identify if any

first-order effects can be attributed to the sharp trip corner geometry. The “hemisphere”

9
(H) trip was selected to identify if the existing database provides any conservatism with

regard to repair scenarios, e.g., STA-54 repairs. The hemisphere trips were manufactured

using two dowels where one interior dowel with a rounded top was inserted into a reamed

hole in the dowel. Lastly, the “gap-filler” trip, identified as either a fence (F) or an angled

fence (AF), was selected to investigate any differences between the existing ground-based

data and the typical flight-type protuberances. For the pizza-box and rounded pizza-box

trips, shim stock of different thicknesses was used to provide the trip height variation, k.

For the fence trips, shim stock cut with dimensions of 0.06000 × H (H is dimension normal

to dowel), as shown in Fig. 4, were used to provide k-variation of the trips. These trip

configurations were completed with the use of a high-temperature adhesive (Loctite 498

Super Bonder) to secure the assembly and to fill in any exposed gaps. A photograph of four

typical trip configurations are shown in Fig. 5 for completeness. The photograph clearly

demonstrates the small scale of the trip-dowel assemblies relative to a dime. Table 3 shows

types and quantities of protuberances manufactured. The trip heights, k, in the table are

the designed values. The as-built heights will be given later in the document.

To secure the dowel inserts into the model, a neodymium magnet was secured to the

bottom of the precision-drilled holes, as depicted in Fig. 6. Blank dowels were used to fit

check all holes to insure proper match to the model OML. Individual adjustment with each

hole could be made by stacking 0.001-in. thick shim stock or 0.003-in. thick double-sided

tape as needed. Once the hole fit check was complete, the blank dowels were also used during

the test to verify the integrity of the overall fit by acquiring untripped data for comparison

to the baseline models without holes. The uncertainty of the trip heights was estimated

to be ±0.0005-in. for all trips. To remove the trip assemblies from the models, a series of

larger magnets were used to extract the dowels/trip assemblies from the drilled holes in the

models.

2.3 Test Instrumentation

Two-color, relative intensity, phosphor thermography was used to measure global temperature to infer the global surface heating distributions on the windward surface of the Orbiter

models [16] - [19]. This technique uses a mixture of phosphors that, when illuminated with

ultraviolet light, fluoresce across regions of the visible spectrum, of which the red and green

wave bands are used. The intensity of the fluorescence is dependent on the amount of incident ultraviolet light and the local surface temperature of the phosphor. This phosphor

mixture (batch #122 used for this test), which is suspended in a silica ceramic binder and applied with an air brush, is used to coat the slip cast silica ceramic models. The final coating

thickness is approximately 0.001 inches. Using a 3-CCD (Charge Coupled Device) camera,

fluorescence intensity images of an illuminated phosphor model exposed to the hypersonic

stream are acquired and converted to temperature mappings via a temperature-intensity

calibration. The temperature calibration uses the ratio of the red and green components

of the image to construct a lookup table which converts the intensities to temperature values. Currently, this calibration, done prior to the test, is valid over a temperature range

from 532 to 800 ◦R. The temperature data from the time-sequenced images taken during a

wind-tunnel run is then reduced to heat-transfer rate at every pixel on the image (and hence

globally on the model) using a heat-transfer rate calculation assuming one-dimensional semiinfinite slab heat conduction [19]. An illustration of the phosphor thermography acquisition

system is shown in Fig. 7.

There are two main advantages of this technique over conventional transient thin-skin

2Batch #12 is given here for completeness. The different batch numbers represent differences in the

preparations of the phosphor coatings used for testing in global phosphor thermography. Some discussion

on the temporal collapse of the heating distributions on Orbiter models using batches #10, 11, and 12 are

given in Ref. [20].

10
calorimeter and thin-film resistance methods. The first is the global resolution of temperature/heating data that provides the detailed information of specific flow features. Surface

heating is determined in a global sense; at every point on the model surface within view of

the camera and at various times during the run. Secondly, the model fabrication method

used produces a coating that does not require re-application between runs, thereby significantly enhancing the efficiency of the phosphor technique. In addition, the slip-casting

model fabrication method is a rapid process whereby, in three to four weeks, a full array

of inexpensive models can be fabricated, complete with various perturbations needed for a

configuration build-up scheme such as variable nose radii and control flap deflections.

Flow condition data were acquired using a 16-bit analog-to-digital facility acquisition

system. The values of the measured uncertainties for the stagnation pressure, Pt, and

stagnation temperature, Tt, are estimated to be ±0.4 psia and ±2.12 ◦R, respectively [13].

The uncertainties in the angle-of-attack of the model are estimated to be ±0.2%. The

heating measurements from the phosphor technique have been estimated to be accurate

to within ±15% [21]. It should be noted, however, that absolute heating measurements

are not required for determining transition onset as this is determined by departure of the

measured non-laminar heating level from a baseline undisturbed laminar value. Run-to-run

repeatability of the heating data for a given model was better than ±4%.

2.4 Data Analysis

For each model, global aeroheating image data were acquired over a range of freestream unit

Reynolds numbers. Transition onset for each model configuration was then inferred from

the corresponding line cuts of the aeroheating image data (centerline cuts and spanwise

cuts at different streamwise stations). Line-cut data were extracted from the aeroheating

images with the IHEAT software package [21]. The results are presented in terms of a nondimensional heat-transfer coefficient ratio h/hF R, where hF R is the theoretical stagnation

point heat-transfer coefficient for a 0.108-in. radius sphere (the nose radius of a 0.9%-scale

Orbiter model) computed using the method of Fay-Riddell [22] for a wall temperature of

540 ◦R. A departure in the normalized mean heat-transfer rate from the laminar baseline

was used as the basis with which to develop the transition criterion. Throughout this

document, an estimate of the incipient transition unit Reynolds number, Reinc, is defined

as the average unit Reynolds number between the last fully laminar condition (Re∞,1) and

the first condition with evidence of laminar departure (Re∞,2), where Re∞ = ρ∞u∞/μ∞.

This basis for defining the incipient conditions will be used throughout this document. For

the freestream unit Reynolds number increments tested, we were able to identify transition

onset to within ±10% (i.e., ±5% uncertainty in the transition parameter, Reθ/Me).

The BLT Tool v.1 was developed using incipient transition data acquired in the Langley

20-Inch Mach 6 Tunnel and a few historical flight data. Incipient transition is defined as

the first evidence of laminar-to-turbulent transition on the windward surface of the Orbiter.

The generalized correlation approach used in this report follows the work summarized in

Ref. [23]. The equation of generalized correlation has the form Ytr = CXn

tr, where Xtr is

the disturbance parameter and Ytr the transition parameter. A line plot represented by

this equation delineates a best estimate boundary for the correlation such that data below

the line denote laminar flow and data above denote turbulent flow. For small disturbance

parameters, the transition parameter should asymptote to a smooth-wall limit, which is

facility dependent. Similarly, for large disturbance parameters, the transition parameter

asymptotes to a limiting lower value – a protuberance limit or a lower threshold limit3. The

current tool [3, 4] assigns as the disturbance parameter k/δ where k is the protuberance

3The protuberance limit implies that further increases in roughness height k has no additional effect on

transition and the lower threshold limit implies that the unit Reynolds number is too low to produce and/or

maintain the turbulence.

11
height and δ the boundary-layer thickness and the transition parameter as Reθ/Me where

Reθ (= ρeueθ/μe) and Me are the momentum thickness Reynolds number and boundarylayer edge Mach number, respectively. The curve coefficient, C = 27, was selected using a

95% confidence level, such that statistically 95% of the incipient transition data lie above

the correlation curve, which introduces some conservatism into the tool. Note that data

obtained in the 20-Inch Mach 6 CF4 Tunnel and the 31-Inch Mach 10 Air Tunnel were not

used in the correlation to evaluate the value of C. The BLT Tool v.1 is expressed as

Reθ

Me

×

k

δ

= C (1)

where the power of n = −1 represents a straight line at −45◦in log-log space.

The flow properties used in the development of the BLT Tool v.1 were derived from an

engineering code called LATCH [5], which utilized a two-layer engineering approach [24]

with inviscid LAURA solutions. The flow properties captured with LATCH are limited to

boundary-layer edge properties and wall conditions. The flow solutions were all computed for

0.75%-scale Orbiter models but the current transition measurements were acquired on 0.9%-

scale Orbiter models. As both models are geometrically similar and exposed to the same

freestream and wall temperature conditions, the solutions for the 0.75%-scale models were

transformed to obtain 0.9%-scale model solutions in lieu of recomputing the flow properties

using LATCH for the 0.9%-scale models. The analysis was done where all flow properties

were transformed at a given freestream unit Reynolds number, Re∞, and prescribed surface

location, X/L ~

ref , for both model scales, i.e.,

Re∞ = Re∞









0.9%

= Re∞









0.75%

(2)

and

X/L ~

ref =



x/Lref , y/Lref 

0.9%=



x/Lref , y/Lref 

0.75%. (3)

Inviscid flow similarity exists for a given freestream condition (assumes weak inviscid/viscid

interaction), such that edge flow properties are the same, i.e.,



Me, Te, Pe, ~ue, ρe, ...

0.9%

=



Me, Te, Pe, ~ue, ρe, ...

0.75%

. (4)

Based on local boundary-layer similarity, the boundary-layer thickness, δ(X/L ~

ref , Re∞), is

assumed proportional to p

X/Ree where Ree = ρeue/μe. For the two different model scales

of interest, this leads to

√

X

δ(X/L ~

ref , Re∞)









0.9%

=

√

X

δ(X/L ~

ref , Re∞)









0.75%

(5)

since the edge unit Reynolds numbers, Ree, are equal per Eq. 4. Utilizing Eq. 3, this is

rearranged to give

δ(X/L ~

ref , Re∞)









0.9%

δ(X/L ~

ref , Re∞)









0.75%

=

s

X0.9%

X0.75%

=

s

L0.9%

L0.75%

= 1.095. (6)

The displacement thickness, δ

∗

(X/L ~

ref , Re∞), and momentum thickness, θ(X/L ~ref , Re∞),

are given by a similar expression, namely



δ0.9%, δ∗

0.9%, θ0.9%

=

s

L0.9%

L0.75% δ0.75%, δ∗

0.75%, θ0.75%

. (7)

12
Applying Eqs. 4 and 7, the scaling for the momentum thickness Reynolds numbers is

Reθ









0.9%

=

θ0.9%

θ0.75%

× Reθ









0.75%

=

s

L0.9%

L0.75% 

×Reθ









0.75%

. (8)

The flow properties on the 0.9%-scale model required for the BLT Tool v.1 were obtained

by first probing the LATCH database for the properties on the 0.75%-scale model at the

desired Re∞ and X/L ~

ref . The disturbance (k/δ) and transition (Reθ/Me) parameters were

then computed using Eqs. 4, 7 and 8.

2.5 Test Matrix and Tunnel Conditions

The proposed test plan of Test 6922 in the 20-Inch Mach 6 Tunnel for the tripped configurations is shown in Table 4. Twelve tripped configurations were proposed between the

five models (models 2 - 6). The proposed plan included the effects of protuberance shape,

orientation, and location. A concise objective for each configuration is given in the table.

Note that ‘shape effect data’ implies both protuberance shape and orientation effects. The

designed incipient unit Reynolds numbers, Reinc, were derived using the BLT Tool v.1

(Eq. 1) with database computed from LATCH. A total of five runs were budgeted for each

configuration. Two Reynolds numbers below the predicted incipient value and two above

were targeted in an attempt to bracket the actual incipient value. A maximum change of

20% was selected between adjacent Reynolds number values. In addition to the proposed

runs noted in Table 4, test runs were planned for the two baseline models (1 and 7) and for

each of the configuration models with blank dowels installed.

Some difficulty was experienced in trying to bracket the incipient Reynolds number

values at the designed incipient lower Reynolds number values (∼ 0.6 × 106/ft) due to

lower Reynolds number limits of the facility and the inability to extract the test section flow

conditions at these low Reynolds numbers using the current process (GASPROPS code [25]).

The test plan was therefore changed in real time and the run matrix as completed is presented

in Table 5. Thirteen tripped and untripped configurations were tested and resulted in a

total of 121 runs during the test entry. For all runs, the model angle-of-attack was set to

40 degrees. The yaw angle, body-flap angle, and aileron angle were fixed at 0 degrees. The

test section flow conditions presented in the tables were computed using the GASPROPS

code with the measured reservoir stagnation pressure Pt, stagnation temperature Tt, and

pitot pressure calibrations of the facility as inputs. The targeted Reynolds numbers were

computed using GASPROPS code by providing the pertinent tunnel conditions. Generally,

aeroheating image data were acquired for each model at four to nine different values of

freestream unit Reynolds number. Additional runs, more than the proposed five, were

typically required to ensure that the model was set to zero sideslip and to provide sufficient

resolution for measuring incipient Reynolds numbers.

3 Results and Discussion

For each Orbiter model configuration, a series of results are presented in the form of a

photograph of the model windward surface (includes close-up images as necessary), global

aeroheating image data for the different freestream unit Reynolds numbers, and line cuts

(centerline and streamwise) of the aeroheating image data. The photographs were all taken

with the models installed in the tunnel but retracted in the sheltered model box position.

The aeroheating image data are shown as colormaps of the normalized heat-transfer coefficient, h/hF R. Test run numbers and the corresponding unit Reynolds numbers are included

with the images for reference. A sketch of the windward surface depicting the trip type,

13
orientation and location are also included with the aeroheating image data. The line cuts

of the aeroheating data were found to be more objective than relying on the colormaps of

the global aeroheating image data to detect the onset of transition. For the runs with a

centerline protuberance, the centerline line cuts over the Reynolds number range are used

to detect laminar departure of h/hF R as a result of that trip. To detect laminar departure resulting from off-centerline protuberances, a series of spanwise line cuts, typically at

x/Lref = 0.8 or 0.9, are plotted for the range of Reynolds numbers tested. The incipient

unit Reynolds number, Reinc, for each of the thirteen model configurations with trips are

presented in Table 6. The unit Reynolds numbers of the last fully laminar value, Re∞,1, and

the first evidence of laminar departure, Re∞,2, along with the LATCH derived disturbance

and transition parameters are also noted in the table. The trip heights, k, in this table are

the as-built heights. All the measured test data are presented below in the form of figures

and tables. The plots of all the test data and accompanying photographs are presented in

Figs. 8 - 90 in chronological run order. For the sake of brevity, only a few key configurations

are discussed to illustrate the process by which Table 6 was populated.

3.1 Untripped Data

The first set of runs were conducted with baseline model 1 to verify consistency with data

acquired on 0.75%-scale models. A photograph showing the windward surface of the model

is presented in Fig. 8. The corresponding global aeroheating image data and line cuts are

given in Figs. 9 - 11. The resulting heating patterns are fairly symmetric, including the

transition front movement in the center region as evident from the elevated heat-transfer

rates. These trends are consistent with earlier measurements on the 0.75%-scale models [6].

The other smooth OML model 7 with the rougher phosphor coating is shown in Fig. 74.

Recall that the surface of models 1 and 7 were intentional processed differently to achieve

different distributed roughness. The resulting aeroheating patterns observed in Fig. 75 are

fairly symmetric except for runs 103 and 99. The heating on the starboard wing is more

intense than that on the port wing. Similar trends are seen in the line cut data presented

in Figs. 76 and 77. The presence of an unintentional isolated roughness, likely a clump of

phosphor particles, is observed in the form of elevated heating in the spanwise line cuts on

the port side of the model (y/Lref ≈ 0.05).

A comparison of the global aeroheating images at similar unit Reynolds numbers between both baseline models (1 and 7) is shown in Fig. 78. Differences in the transition

locations due to the distributed roughness are evident in this figure and the trends are

consistent with expectations, i.e., transition occurs earlier for the surface with the larger

distributed roughness. Recall from the discussion in Section 2.2 that four surface roughness measurements were obtained on both models, two on the symmetry plane and one on

each wing. The mean values of the four roughness averages, Ra, for model 1 and model 7

are Ra = 177 μ-in. (or root-mean-square roughness, Rq = 220 μ-in.) and Ra = 281 μ-in.

(Rq = 365 μ-in.), respectively. The streamwise line cuts of the heating data corresponding to Fig. 78 are shown in Fig. 79 (note that run 3 data are included for comparison).

Transition onset on the symmetry plane for both runs 3 (Re∞ ≈ 5.45 × 106/ft) and 99

(Re∞ ≈ 3.78 × 106/ft) occurred at x/Lref ≈ 0.57. The transition Reynolds number, based

on freestream conditions and the centerline distance from the model leading edge to the

transition onset location, for model 1 (run 3) is Re∞,tr ≈ 3.0×106 and for model 7 (run 99)

is Re∞ ≈ 2.1 × 106. The transition parameters for models 1 and 7 are Reθ/Me ≈ 295 and

245, respectively. The corresponding k/δ (= Ra/δ) values for distributed roughnesses at

x/Lref ≈ 0.57 of models 1 and 7 are k/δ ≈ 0.012 and 0.018, respectively. These k/δ values

are based on mean values of the symmetry plane roughness averages. These mean values for

models 1 and 7 are Ra = 156 μ-in. (Rq = 193 μ-in.) and Ra = 284 μ-in. (Rq = 361 μ-in.),

respectively. The k/δ values for the distributed surface roughness are more than an order

14
of magnitude smaller than those for the isolated three-dimensional roughnesses used in this

study. The corresponding Rek (= ρkukk/μk) values at incipient transition locations for the

distributed roughnesses are order one (based on Navier-Stokes solution database) and are

not believed to have adverse effects on the discrete roughness results which have Rek values

two orders of magnitude larger than the distributed results.

3.2 Tripped Data

Before tripped configurations were tested, blank dowels (no trips bonded to dowels) were

installed in each model to verify the integrity of the fit, i.e., to insure the dowel/hole combinations do not prematurely trip the downstream flow. This was generally done for Reynolds

numbers up to at least twice the designed incipient values. In most cases, the phosphor

coatings were chipped around the holes as a result of the constant insertion and removal of

the trip assemblies. To mitigate any adverse effects of the chipped coatings with respect to

premature transition, dental plaster was generally used to fill the chipped areas when the

amount of lost coating became significant. In the close up photographs, the areas around

the holes that were filled with dental plaster appear white in the images. A close-up photograph and aeroheating data for model 2 (trip located on centerline at x/Lref = 0.1) with

a blank dowel inserted are shown in Figs. 12 - 14. Note that blank dowels are denoted by

red x’s in the model sketches (see Fig. 12). The aeroheating line cuts also include data

from baseline model 1 (denoted M1 in the plot legend) for comparison at a comparable

Reynolds number. Also compare the run 6 colormap image imbedded in Fig. 13 to the

run 1 image in Fig. 9. The resulting heating results are nearly identical to model 1 up to

Re∞ = 2.08×106/ft, which is twice the designed incipient Reynolds number for the trip configurations with model 2. Next, consider configuration 2 (see Table 6) where a fence (F) trip

with height k = 0.00800 was installed in model 2. The associated close-up photograph and

aeroheating data are given in Figs. 19 - 22. The orientation of the trip is clearly illustrated

in the Fig. 20 where the trailing edge of the fence points towards the starboard (STB) side

of the Orbiter. Positive angle notations used in the figures and tables indicate a clockwise

rotation of the trip relative to the model centerline. The heating patterns resulting from

the trip are slightly asymmetric, perhaps due to the asymmetry of the fence trip. The run

16 image and line cuts clearly show an increase in heating downstream of the trip from the

observed laminar values of runs 17 and 19. The expected incipient value derived from the

BLT Tool v.1 was Re∞ ≈ 1.0 × 106/ft, while the resulting incipient value from the current

data based on the average approach is Reinc = 0.685 × 106/ft, i.e., the average Re∞ of runs

17 and 16. Therefore, the BLT Tool v.1 predicts later incipient transition than realized in

the test implying that the tool is nonconservative for this configuration. It is important to

recall that the tool was designed to be conservative (95% confidence limit) for the existing

database.

Next, consider configuration 3 with three trips located at x/L = 0.5 on model 3. A closeup photograph showing all three trips and a table with trip types and locations are given in

Fig. 30. The outboard trips were intended to be on the attachment lines. The aeroheating

data and line cuts are shown in Figs. 31 - 33. The resulting heating patterns are fairly

symmetric. The run 41 image shows a slight increase in heating downstream of the centerline

trip. The resulting incipient value from the centerline fence trip is Reinc = 1.14 × 106/ft

based on the line cuts in Figs. 32 and 33. The freestream unit Reynolds number was increased

to about three times the designed incipient value and no elevated heating resulting from the

attachment-line trips (PB and H) was observed downstream. The attachment-line trips are

postulated to be too far outboard such that the resulting disturbances are being swept to

the leeside of the Orbiter model. This was observed for all of the configurations tested with

model 3; consequently, we were unable to acquire off-centerline incipient transition data for

the model 3 configurations. It should be noted that attachment-line data were acquired in

15
the previous test at Mach 6 on the 0.75%-scale models at this forebody location [6]. There

is a minor difference in the tabulated trip locations noted in this study and those noted in

Ref. [6]. For the current study, the trip locations are based on the centroidal locations of

the trips, i.e., the hole centers. In the previous study [6], the pizza-box trips were located

based on the upstream vertex of the trips. It is plausible that the upstream placement of

the trips by one half the trip length in the current study relative to the previous study is

partly responsible for this inconsistency.

The photograph and aeroheating data for configuration 6A on model 4 are presented

in Figs. 44 - 47. Three trips are located at x/Lref = 0.7 for this configuration, one on

the centerline and two outboard (see table imbedded in Fig. 44). The outboard trips for

model 4 were intended to be inboard of the attachment lines. The heating patterns in the

global aerothermal images for configuration 6A are fairly symmetric. The run 56 image and

line cuts show a slight increase in heating downstream of the centerline trip. The resulting

incipient value from the centerline fence trip is Reinc = 0.945 × 106/ft. The outboard trips

are clearly inboard of the attachment lines and are evident in the images, as the disturbance

wedges are being swept nearly directly aft. Elevated heating due to the port side trip is

first evident in the aeroheating data of run 58 (see line cuts). The resulting incipient data

from this port side pizza-box trip is Reinc = 0.765 × 106/ft. Similarly, elevated heating due

to the starboard side trip is first evident in run 60. The resulting incipient value from the

starboard side hemisphere trip is Reinc = 1.65 × 106/ft. Clearly, the pizza-box trip is more

effective than the hemisphere trip for this outboard trip location.

Consider configuration 6C on model 4. The photograph and heating data are shown in

Figs. 52 - 55. The centerline and starboard trips are a fence and an angled fence, respectively,

oriented parallel to the model centerline (see sketch in Fig. 53). The port trip is a pizza-box

trip where the diagonal line from the upstream vertex makes approximately a −22.5

◦ angle

relative to the model centerline (negative value implies a counterclockwise rotation). The

resulting heating patterns are fairly symmetric. The run 72 image and line cuts show an

increase in heating downstream of the centerline fence trip. The resulting incipient value

from the centerline fence trip is Reinc = 2.40 × 106/ft compared to the designed value of

Re∞ ≈ 1.0×106/ft. As anticipated, the BLT Tool v.1 is very conservative for the centerline

fence trip due to the orientation of the fence. Per line cuts in Fig. 55, the resulting incipient

data from the port pizza-box trip is Reinc = 0.97 × 106/ft which is within the experimental

uncertainty of the design value. The starboard incipient data for the angled fence appeared

to be contaminated by a mismatch between the dowel and the OML due to significant

coating lost around the edge of the hole; consequently, no transition resulting from the

starboard trip data was acquired for this configuration.

Data are presented here for configuration 8 on model 5 where three trips are located

at x/Lref = 0.74. The two outboard trips for model 5 were intended to be located just

inboard of the attachment lines. The trips are a fence trip at +45◦, a fence trip at −45◦

and a pizza-box trip on the model centerline, port side and starboard side, respectively. A

close-up photograph and table with pertinent trip information are given in Fig. 83. The

designed incipient Reynolds number for configuration 8 is Re∞ ≈ 0.6×106/ft. As is evident

in Figs. 84 - 86, the run 109 image and line cuts show an increase in heating downstream of

the centerline fence trip. The resulting incipient Reynolds number from the centerline fence

trip is Reinc = 1.0 × 106/ft. The attachment line trips appear to be near the attachment

line, as designed, since the disturbance wedges stay near to the wing leading edge. Increased

heating downstream of the port fence trip is first observed in run 111 (see spanwise line cuts

in Fig. 86), resulting in an incipient value on the port side of Reinc = 0.505 × 106/ft. Note

that the orientation of the port fence trip is nearly aligned with the wing leading edge

implying that the fence is in the general direction of the inviscid edge flow. One might

assume that due to the small relative angle of the fence to the local edge streamlines this

orientation may be somewhat less effective at promoting boundary-layer transition, but the

16
data do not support that conclusion. In the outboard regions, there is crossflow generated

by spanwise gradients that leads to flow angularity between the incoming boundary-layer

flow and the fence. This is in contrast to the centerline trip in configuration 6C discussed

earlier where there is no crossflow on the model centerline. Increased heating downstream

of the starboard pizza-box trip is first seen in run 113 and the resulting incipient value is

Reinc = 0.665 × 106/ft which is consistent with the designed value. The port fence trip is

more effective than the starboard pizza-box trip for this configuration as demonstrated by

the lower Reinc and k values for the port fence trip.

Consider configuration 8A on model 5 shown in Fig. 87 where three trips are located at

x/Lref = 0.74. The trips are a pizza-box trip, a fence trip at +45◦ and an angled fenced

trip at −45◦ on the model centerline, port side and starboard side, respectively. Note that

pertinent trip information is imbedded in the table of the figure. The global images and

line cuts are given in Figs. 88 - 90. The resulting heating patterns are symmetric. The

run 115 image and line cuts show a slight increase in heating downstream of the centerline

pizza-box trip resulting in an incipient value of Reinc = 1.0 × 106/ft. The port fence trip

orientation for this configuration was achieved by simply rotating the fence in configuration

8 by 90◦

. Evidence of elevated heating due to the port fence trip is first apparent in run 118,

corresponding to Reinc = 0.86 × 106/ft. Note that the port fence trip with the orientation

in configuration 8 (nearly aligned to the wing leading edge) is more effective than the fence

trip in configuration 8A (oriented nearly perpendicular to the wing leading edge). This

observation was somewhat counter intuitive to our expectations based solely on the relative

alignment of the edge flow and fence trip. Similarly, the resulting incipient value from the

starboard angled fence is Reinc = 1.36 × 106/ft.

This concludes the brief discussion overview of the configurations tested, with and without protuberances. The incipient transition data resulting from discrete protuberances are

tabulated in Table 6. These results are plotted in Fig. 91 along with the previous Mach

6 data in the BLT Tool v.1 correlation space. It should be noted that the existing data

presented in the figure are a slight variation from those used to develop the BLT Tool v.1

correlation [3, 4]. The incipient values used to develop Version 1 of the BLT Tool were

generally defined as the first value of laminar departure versus the average approach used

for this analysis. However, with this change in the definition of the incipient values, both

approaches were found to be consistent. The transition and disturbance parameters given

in Table 6 are based on the LATCH database. The experimental correlation constant, C,

for each configuration is also given in the table. For all except two values (shown as bold

in the table), the BLT Tool v.1 with C = 27 is conservative as designed. The two nonconservative configurations happen to be fences oriented at 45 degrees relative to the model

centerline at x/Lref locations of 0.1 and 0.74. The tool was most conservative (C = 74) for

a fence aligned with the flow on the model centerline at x/Lref = 0.70. In the correlation

plot presented in Fig. 91, the TEI data demonstrate more scatter than the existing Mach 6

data. This increased scatter is expected since the TEI data includes the effects of protuberance shape and orientation on transition onset not captured within the previous Version 1

dataset [6].

4 Summary

This report documents the TEI wind-tunnel test on 0.9%-scale Shuttle Orbiter models in

the Langley 20-Inch Mach 6 Tunnel. The uses of this experimental database are to assess the

applicability of the BLT Tool v.1 for different protrusion shapes and to ultimately develop

a more comprehensive version of the BLT Tool to include all of the available gound-based

and flight data. Phosphor thermography was used to measure the global aeroheating on the

windward surface of the Orbiter models in order to distinguish laminar and/or turbulent

17
heating. A Reynolds-number sweep was performed to identify boundary-layer transition

onset for each model configuration. Transition sensitivity to various protuberance types,

more representative of realistic trips, were examined to establish if the BLT Tool v.1 is

still conservative for protuberances other than the pizza-box trips. The protuberance types

include pizza-box, rounded pizza-box, fence, angled fence, and hemisphere trips with heights

in the range of 0.00600 ≤ k ≤ 0.01100 (0.22 < k/δ < 0.52) at axial locations in the range

of 0.10 ≤ x/Lref ≤ 0.85. The effect of distributed roughness on a secondary baseline

model with surface roughness larger than the primary baseline model with nominal surface

roughness was examined. The results clearly demonstrate earlier transition onset on the

acreage region of windward surface for the model with the larger surface roughness (∼ 1/3

reduction in Re∞,tr). The mean values of the measured roughness averages along the model

symmetry plane for the primary and secondary baseline models are Ra = 156 μ-in. and

Ra = 284 μ-in., respectively.

The protuberance test results are summarized in Table 6 and presented in Fig. 91. Some

general observations from this study are highlighted below.

• Some protuberance geometry effects were observed for fence and pizza-box trips.

Within experimental uncertainty, fence trips oriented at ±45◦ appear more effective

than pizza-box and hemisphere trips for a given trip height, k, and model location.

Hemisphere protuberances are the least destabilizing trips tested in the nominal orientations, i.e., fences at ±45◦ and pizza boxes with diagonals parallel to the model

centerline.

• Pizza-box trips appear more effective in the traditional orientation (diagonal from

upstream vertex parallel to model centerline) at the outboard locations for x/Lref =

0.70 than for the other orientations tested.

• Fence trips on the Orbiter centerline appear to be most effective for transition onset

at orientations of ±45◦, least effective at 0◦, and have an intermediate effectiveness

at 90◦. The fence trip oriented at 0◦ on the model centerline is the least destabilizing

trip configuration tested.

• Fences aligned almost parallel to the wing leading edge near the attachment line are

very effective. Care must be taken not to falsely assume that outboard gap fillers are

ineffective if they are closely aligned with the wing leading edge.

• Fences approximately normal to the wing leading edge are less effective than fences

nearly parallel to wing leading edge. This may seem somewhat counter intuitive.

• At x/Lref = 0.85, the BLT Tool v.1 is measurably conservative for the protuberance

types tested (pizza-box, rounded pizza-box, and fence trips). This result may be

significant as it implies that the tool may predict early transition for protuberances

at aft locations on the Orbiter.

• BLT Tool v.1 is conservative for all newly acquired incipient data except for two data

points with fence trips at x/Lref = 0.10 on the centerline and at x/Lref = 0.74 near

the attachment line (fence nearly parallel to the wing leading edge).

• Shape effects and orientation effects are mostly confined to the scatter in the existing

Mach 6 data, i.e., no significant first-order effects with protuberance type are apparent

in the existing Version 1 of the BLT Tool.

18
References

1. Columbia Accident Investigation Board Final Reports, Vol. I-VI [online resource],

URL: http://caib.nasa.gov/ [cited August and October 2003].

2. Campbell, C. H., Anderson, B., Bourland, G., Bouslog, S., Cassady, A., Horvath,

T. J., Berry, S. A., Gnoffo, P. A., Wood, W. A., Reuther, J. J., Driver, D.

M., Chao, D. C., Hyatt, J., and Picetti, D., “Orbiter Return To Flight Entry

Aeroheating,” AIAA Paper 2006-2917, June 2006.

3. Berry, S. A., Horvath, T. J., Green, F. A., Kinder, G. R., and Wang, K. C.,

“Overview of Boundary Layer Transition Research in Support of Orbiter Return

To Flight,” AIAA Paper 2006-2918, June 2006.

4. Horvath, T. J., Berry, S. A., Merski, N. R., Berger, K. T., Buck, G. M., Liechty,

D. S., and Schneider, S. P., “Shuttle Damage/Repair from the Perspective of

Hypersonic Boundary Layer Transition - Experimental Results,” AIAA Paper

2006-2919, June 2006.

5. Greene, F. A. and Hamilton, H. H., “Development of a Boundary Layer Properties

Interpolation Tool in Support of Orbiter Return to Flight,” AIAA Paper 2006-

2920, June 2006.

6. Liechty, D. S., Berry, S. A., and Horvath, T. J., “Shuttle Return To Flight Experimental Results: Protuberance Effects on Boundary Layer Transition,” NASA

TM-2006-214306, May 2006.

7. Liechty, D. S., Horvath, T. J., and Berry, S. A., “Shuttle Return to Fight Experimental Results: Cavity Effects on Boundary Layer Transition,” NASA TM2006-214305, May 2006.

8. McGinley, C. B, Berry, S. A., Kinder, G. R., Barnwell, M., Wang, K. C., and

Kirk, S. K., “Review of Orbiter Flight Boundary Layer Transition Data,” AIAA

Paper 2006-2921, June 2006.

9. Miller, C. G., “Hypersonic Aerodynamic/Aerthermodynamic Testing Capabilities

at Langley Research Center,” AIAA Paper 1992-3937, July 1992.

10. Kegerise, M. A., King, R. A., and Berry, S. A., “Wind Tunnel Test in Support

of STS-121: Protuberance Effects on Boundary-Layer Transition,” NASA JSC

EG-SS-07-06, 2007.

11. Cassady, A. M., Bourland, G., King, R. A., Kegerise, M. A., Marichalar, J., Kirk,

B. S., and Trevi ̃no, L., “MH-13 Space Shuttle Orbiter Aerothermodynamic Test

Report,” NASA TP-2007-214758, 2007.

12. AAEC Research Staff, LENS Brochure, Capabilities and Technologies, Buffalo,

NY 2004.

13. Rhode, M. N., and DeLoach R., “Hypersonic Wind Tunnel Calibration Using the

Modern Design of Experiments,” AIAA Paper 2005-4274, July 2005.

14. Bibb, K. L, “2002 Shuttle Orbiter CAD Geometry, as used in Support of the

Columbia Accident Investigation and Return-to-Flight,” NASA JSC Orbiter Entry Aeroheating Note OEAN-0305-005.

19
15. Buck, G. M., Powers, M. A., Griffith, M. S., Hopkins, J. W., Veneris, P. H., and

Kuykendoll, K. A., “Fabrication of 0.0075-Scale Orbiter Phosphor Thermography Test Models for Shuttle RTF Aeroheating Studies,” NASA TM-2006-214507,

November 2006.

16. Buck, G. M., “Automated Thermal Mapping Techniques Using Chromatic Image

Analysis,” NASA TM-101554, April 1989.

17. Buck, G. M., “Surface Temperature/Heat Transfer Measurement Using a Quantitative Phosphor Thermography System,” AIAA Paper 91-0064, January 1991.

18. Merski, N. R., “A Relative-Intensity, Two-Color Phosphor Thermography System,” NASA TM-104123, September 1991.

19. Merski, N. R., “Global Aeroheating Wind-Tunnel Measurements Using Improved

Two-Color Phosphor Thermography Method,” Journal of Spacecraft and Rockets,

Vol. 36, No. 2, 1999, pp. 160-170.

20. Kegerise, M. A., King, R. A., and Berry, S. A., “Cavity Effects on Space Shuttle

Orbiter Boundary-Layer Transition,” NASA TM-2008-215113, March 2008.

21. Merski, N. R., “Reduction and Analysis of Phosphor Thermography Data with

IHEAT Software Package,” AIAA Paper 98-0712, January 1998.

22. Fay, J. A., and Riddell, F. R. “Theory of Stagnation Point Heat Transfer in

Dissociated Air,” Journal of the Aeronautical Sciences, Vol. 25, No. 2, 1958,

pp. 73-85.

23. Reda, D. C., “Review and Synthesis of Roughness-Dominated Transition Correlations for Reentry Applications,” Journal of Spacecraft and Rockets, Vol. 39,

No. 2, 2002, pp. 161-167.

24. Hamilton, H. H., DeJarnette, F. R., and Weilmuenster, K. J. “Applications of Axisymmetric Analog for Calculating Heating in Three-Dimensional Flows,” Journal

of the Spacecraft and Rockets, Vol. 24, No. 4, 1987, pp. 296-302.

25. Hollis, B. R., “Real-Gas Flow Properties for NASA Langley Research Center Aerothermodynamic Facilities Complex Wind Tunnels,” NASA CR-4755,

September 1996.

20
Table 1. Plug locations for the tripped model configurations.

Model 2 Model 3 Model 4 Model 5 Model 6

x/Lref y/Lref x/Lref y/Lref x/Lref y/Lref x/Lref y/Lref x/Lref y/Lref

0.10 0 0.50 0 0.70 0 0.74 0 0.85 0

– – 0.50 0.1008 0.70 0.1658 0.74 0.2348 – –

– – 0.50 -0.1008 0.70 -0.1658 0.74 -0.2348 – –

Table 2. Fiducial locations on all the final models.

x/Lref y/Lref

0.05 0

0.30 0

0.80 0

1.00 0

0.70 0.2298

0.70 -0.2298

0.80 0.2937

0.80 -0.2937

Table 3. Protuberance dimensions and quantities requested to be manufactured. Note that

the trip heights, k, in the table are the designed values, not the as-built heights.

Trip Type k {inch} Quantity

0.006 3

PB 0.007 3

0.010 1

0.012 1

RPB 0.010 1

0.012 1

0.005 1

F 0.006 1

0.007 3

0.010 3

0.012 2

AF 0.006 2

H 0.008 2

TOTAL 24

21
Table 4. Proposed test plan and test conditions for models with protuberances (baseline configuration tests not included).

Config. Model Nominal Reinc/ft x/Lref y/Lref Protuberance

k k/δ Objective Runs per

Mach (Design) Type (Loc) {inch} Config.

1 2 6 1.0 × 10

6 0.10 0 PB (CL) 0.007 0.378 Repeat of existing data 5

2 2 6 1.0 × 10

6 0.10 0 F (CL) 0.007 0.378 Shape effect data 5

3 2 6 0.6 × 10

6 0.10 0 F (CL) 0.012 0.506 Shape effect data 5

0.50 0 F (CL) 0.012 0.333 Shape effect data

4 3 6 0.6 × 10

6 0.50 -0.1008 PB (Port AL) 0.012 0.405 Repeat of existing data 5

0.50 0.1008 RPB (STB AL) 0.012 0.405 Shape effect data

0.50 0 PB (CL) 0.007 0.250 Repeat of existing data

5 3 6 1.0 × 10

6 0.50 -0.1008 F (Port AL) 0.007 0.304 Shape effect data 5

0.50 0.1008 H (STB AL) 0.008 0.348 Shape effect data

0.70 0 F (CL) 0.010 0.250 Shape effect data

6 4 6 0.6 × 10

6 0.70 -0.1658 PB (Port side) 0.010 0.370 Data inboard shock interaction 5

0.70 0.1658 RPB (STB side) 0.010 0.370 Data inboard shock interaction

0.70 0 PB (CL) 0.006 0.193 Extension of existing data

7 4 6 1.0 × 10

6 0.70 -0.1658 F (Port side) 0.006 0.286 Data inboard shock interaction 5

0.70 0.1658 AF (STB side) 0.006 0.286 Data inboard shock interaction

0.74 0 F (CL) 0.010 0.247 Shape effect data

8 5 6 0.6 × 10

6 0.74 -0.2348 F (Port side) 0.007 0.400 Shape effect data 5

0.74 0.2348 PB (STB side) 0.007 0.400 Extension of existing data

0.74 0 PB (CL) 0.006 0.191 Extension of existing data

9 5 6 1.0 × 10

6 0.74 -0.2348 F (Port side) 0.005 0.368 Shape effect data 5

0.74 0.2348 H (STB side) 0.008 0.588 Shape effect data

10 6 6 1.0 × 10

6 0.85 0 PB (CL) 0.006 0.179 Repeat of existing data 5

11 6 6 1.0 × 10

6 0.85 0 AF (CL) 0.006 0.179 Shape effect data 5

12 6 6 0.6 × 10

6 0.85 0 F (CL) 0.010 0.232 Shape effect data 5

Lref = 11.52 in. Total Potential Protuberance Runs = 60

22
Table 5. Test 6922 final run log.

Run Date Model Config. Re∞/ft Pt Tt Trips

×10−6 {psia} {◦F} Port Side Centerline Starboard Side

(2006) x/Lref y/Lref Type k {in.} y/Lref Type k {in.} y/Lref Type k {in.}

1 8/21 1 Bsln 1.90 114 442 - - - - - - - - - - 2 8/21 1 Bsln 3.74 230 447 - - - - - - - - - - 3 8/21 1 Bsln 5.45 350 469 - - - - - - - - - - 4 8/21 1 Bsln 0.57 30 397 - - - - - - - - - - 5 8/21 1 Bsln 4.49 291 474 - - - - - - - - - - 6 8/22 2 Bsln 2.08 126 445 0.10 - - - - - - - - - 7* 8/22 2 Bsln 3.77 231 445 0.10 - - - - - - - - - 8* 8/22 2 Bsln 2.08 125 442 0.10 - - - - - - - - - 9 8/22 2 Bsln 2.08 125 443 0.10 - - - - - - - - - 10 8/22 2 1 1.78 107 441 0.10 - - - 0 PB 0.008 - - - 11 8/22 2 1 1.09 61 414 0.10 - - - 0 PB 0.008 - - - 12 8/23 2 1 1.25 71 420 0.10 - - - 0 PB 0.008 - - - 13 8/23 2 1 0.86 47 409 0.10 - - - 0 PB 0.008 - - - 14 8/23 2 2 1.77 106 445 0.10 - - - 0 F 0.008 - - - 15 8/23 2 2 1.06 59 414 0.10 - - - 0 F 0.008 - - - 16 8/23 2 2 0.80 46 408 0.10 - - - 0 F 0.008 - - - 17 8/23 2 2 0.57 30 397 0.10 - - - 0 F 0.008 - - - 18* 8/23 2 2 0.25 - - 0.10 - - - 0 F 0.008 - - - 19 8/23 2 2 0.45 22 377 0.10 - - - 0 F 0.008 - - - 20 8/23 2 2 1.25 71 419 0.10 - - - 0 F 0.008 - - - 21 8/24 3 Bsln 1.89 113 439 0.50 - - - - - - - - - 22 8/24 3 Bsln 3.74 228 447 0.50 - - - - - - - - - 23* 8/24 3 5 1.78 106 440 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.014

24* 8/24 3 5 1.78 106 439 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.00725 8/24 3 5 1.76 105 441 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.00726 8/24 3 5 2.07 125 443 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.00727 8/24 3 5 2.50 153 446 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.00728 8/24 3 5 1.07 60 418 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.00729 8/24 3 5 1.22 69 421 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.00730 8/24 3 5 1.50 86 425 0.50 -0.1008 F 0.007 0 PB 0.008 0.1008 H 0.007

* Data not acquired for these runs. ‘Bsln’ refers to baseline (no trips). y/Lref > 0 implies STB side and y/Lref < 0 Port side.

Fence trips are oriented 45 degrees relative to the model centerline unless noted otherwise.Pizza-box and rounded pizza-box trips are oriented with a diagonal line parallel (i.e., faces of trip ±45◦) to model centerline unless noted otherwise.

23
Table 5. Test 6922 final run log – (Cont).

Run Date Model Config. Re

∞/ft

Pt Tt Trips

×10

−6

{psia} {

◦F} Port Side Centerline Starboard Side

(2006) x/Lref y/Lref Type k {in.} y/Lref Type k {in.} y/Lref Type k {in.}

31 8/25 3 5 3.06 185 440 0.50 -0.1008

F 0.007 0 PB 0.008 0.1008

H 0.007

32 8/25 3 5 1.64 96 428 0.50 -0.1008

F 0.007 0 PB 0.008 0.1008

H 0.007

33 8/25 3 5 3.43 212 448 0.50 -0.1008

F 0.007 0 PB 0.008 0.1008

H 0.007

34 8/25 3 5A 2.06 124 441 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

35 8/25 3 5A 1.49 86 424 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

36 8/25 3 5A 1.09 61 414 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

37 8/25 3 5A 1.23 70 420 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

38 8/25 3 5A 3.01 184 446 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

39 8/25 3 5A 2.55 155 442 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

40 8/25 3 5A 3.38 209 450 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

41 8/25 3 5A 1.18 67 422 0.50 -0.1008 PB 0.008 0 F 0.007 0.1008

H 0.007

42 8/28 3 5B 1.51 88 428 0.50 -0.1008 PB 0.008 0 H 0.007 0.1008

F 0.007

43 8/28 3 5B 1.78 107 443 0.50 -0.1008 PB 0.008 0 H 0.007 0.1008

F 0.007

44 8/28 3 5B 1.23 70 423 0.50 -0.1008 PB 0.008 0 H 0.007 0.1008

F 0.007

45 8/28 3 5B 2.10 126 441 0.50 -0.1008 PB 0.008 0 H 0.007 0.1008

F 0.007

46 8/28 3 5B 2.56 155 443 0.50 -0.1008 PB 0.008 0 H 0.007 0.1008

F 0.007

47* 8/28 4 Bsln 2.53 153 441 0.70 - - - - - - - - - 48 8/28 4 Bsln 3.70 227 445 0.70 - - - - - - - - - 49 8/28 4 Bsln 4.49 290 472 0.70 - - - - - - - - - 50 8/28 4 Bsln 3.75 231 447 0.70 - - - - - - - - - 51 8/28 4 Bsln 2.07 125 444 0.70 - - - - - - - - - 52 8/28 4 Bsln 2.55 156 448 0.70 - - - - - - - - - 53 8/28 4 Bsln 1.08 61 416 0.70 - - - - - - - - - 54* 8/29 4 Bsln 3.04 185 441 0.70 - - - - - - - - - 55 8/29 4 Bsln 3.05 186 444 0.70 - - - - - - - - - 56 8/29 4 6A 1.04 58 413 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

57 8/29 4 6A 0.68 35 398 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

58 8/29 4 6A 0.85 46 407 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

59* 8/30 4 6A 1.78 106 439 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

60 8/30 4 6A 1.79 107 443 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

24
Table 5. Test 6922 final run log – (Cont).

Run Date Model Config. Re

∞/ft

Pt Tt Trips

×10

−6

{psia} {

◦F} Port Side Centerline Starboard Side

(2006) x/Lref y/Lref Type k {in.} y/Lref Type k {in.} y/Lref Type k {in.}

61 8/30 4 6A 1.50 87 425 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

62 8/30 4 6A 1.22 69 418 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

63 8/30 4 6A 2.06 124 443 0.70 -0.1658 PB 0.008 0 F 0.007 0.1658

H 0.007

64 8/30 4 6B 1.06 59 414 0.70 -0.1658 PB

1 0.008 0 F

1 0.007 0.1658 AF

1 0.006/0.004

65 8/30 4 6B 1.50 86 425 0.70 -0.1658 PB

1 0.008 0 F

1 0.007 0.1658 AF

1 0.006/0.004

66 8/30 4 6B 0.85 46 409 0.70 -0.1658 PB

1 0.008 0 F

1 0.007 0.1658 AF

1 0.006/0.004

67 8/30 4 6B 1.23 70 420 0.70 -0.1658 PB

1 0.008 0 F

1 0.007 0.1658 AF

1 0.006/0.004

68 8/31 4 6B 1.79 107 440 0.70 -0.1658 PB

1 0.008 0 F

1 0.007 0.1658 AF

1 0.006/0.004

69 8/31 4 6C 1.79 107 440 0.70 -0.1658 PB

3 0.008 0 F

2 0.007 0.1658 AF

2 0.006/0.004

70 8/31 4 6C 1.08 60 414 0.70 -0.1658 PB

3 0.008 0 F

2 0.007 0.1658 AF

2 0.006/0.004

71 8/31 4 6C 0.86 47 408 0.70 -0.1658 PB

3 0.008 0 F

2 0.007 0.1658 AF

2 0.006/0.004

72 8/31 4 6C 2.56 155 441 0.70 -0.1658 PB

3 0.008 0 F

2 0.007 0.1658 AF

2 0.006/0.004

73 8/31 4 6C 3.04 186 447 0.70 -0.1658 PB

3 0.008 0 F

2 0.007 0.1658 AF

2 0.006/0.004

74 8/31 4 6C 2.23 134 441 0.70 -0.1658 PB

3 0.008 0 F

2 0.007 0.1658 AF

2 0.006/0.004

75 8/31 6 Bsln 3.04 185 444 0.85 - - - - - - - - - 76 8/31 6 Bsln 1.92 115 441 0.85 - - - - - - - - - 77 8/31 6 Bsln 3.80 231 441 0.85 - - - - - - - - - 78 8/31 6 Bsln 4.50 290 472 0.85 - - - - - - - - - 79 8/31 6 Bsln 5.41 350 473 0.85 - - - - - - - - - 80* 9/1 6 12 1.08 60 414 0.85 - - - 0 F 0.011 - - - 81 9/5 6 12 1.07 60 419 0.85 - - - 0 F 0.011 - - - 82* 9/5 6 12 0.77 42 411 0.85 - - - 0 F 0.011 - - - 83 9/5 6 12 0.91 50 411 0.85 - - - 0 F 0.011 - - - 84 9/5 6 12 1.50 87 428 0.85 - - - 0 F 0.011 - - - 85 9/5 6 12 0.77 41 408 0.85 - - - 0 F 0.011 - - - 86 9/5 6 12 1.78 107 443 0.85 - - - 0 F 0.011 - - - 87 9/5 6 12B 1.06 59 414 0.85 - - - 0 PB 0.010 - - - 88 9/5 6 12B 1.49 86 424 0.85 - - - 0 PB 0.010 - - - 89* 9/6 6 12B 2.00 125 450 0.85 - - - 0 PB 0.010 - - - 90 9/6 6 12B 2.07 125 443 0.85 - - - 0 PB 0.010 - - -

1 Face of trip perpendicular to model centerline.

2 Face of trip parallel to model centerline.3 Upstream inboard face of trip

∼ 22.5 degrees relative to model centerline.

25
Table 5. Test 6922 final run log – (Cont).

Run Date Model Config. Re

∞/ft

Pt Tt Trips

×10

−6

{psia} {

◦F} Port Side Centerline Starboard Side

(2006) x/Lref y/Lref Type k {in.} y/Lref Type k {in.} y/Lref Type k {in.}

91 9/6 6 12B 1.79 108 442 0.85 - - - 0 PB 0.010 - - - 92 9/6 6 12B 2.31 140 443 0.85 - - - 0 PB 0.010 - - - 93 9/6 6 12A 1.07 60 415 0.85 - - - 0 RPB 0.010 - - - 94 9/6 6 12A 1.78 107 442 0.85 - - - 0 RPB 0.010 - - - 95 9/6 6 12A 1.23 70 420 0.85 - - - 0 RPB 0.010 - - - 96 9/6 6 12A 1.51 87 426 0.85 - - - 0 RPB 0.010 - - - 97 9/6 6 12A 2.08 125 441 0.85 - - - 0 RPB 0.010 - - - 98 9/6 7 Bsln 3.77 231 445 - - - - - - - - - - 99 9/6 7 Bsln 3.78 231 444 - - - - - - - - - - 100 9/7 7 Bsln 1.92 115 440 - - - - - - - - - - 101 9/7 7 Bsln 0.59 30 399 - - - - - - - - - - 102* 9/7 7 Bsln 3.01 184 445 - - - - - - - - - - 103 9/7 7 Bsln 3.03 185 446 - - - - - - - - - - 104 9/7 7 Bsln 4.51 290 469 - - - - - - - - - - 105 9/7 5 Bsln 2.07 124 441 - - - - - - - - - - 106* 9/7 5 Bsln 2.56 156 445 - - - - - - - - - - 107* 9/7 5 Bsln 2.53 155 446 - - - - - - - - - - 108 9/7 5 Bsln 2.54 155 446 - - - - - - - - - - 109 9/7 5 8 1.06 59 414 0.74 -0.2348

F 0.007 0 F 0.011 0.2348 PB 0.008

110 9/8 5 8 0.94 51 407 0.74 -0.2348

F 0.007 0 F 0.011 0.2348 PB 0.008

111 9/8 5 8 0.57 29 396 0.74 -0.2348

F 0.007 0 F 0.011 0.2348 PB 0.008

112 9/8 5 8 0.44 22 395 0.74 -0.2348

F 0.007 0 F 0.011 0.2348 PB 0.008

113 9/8 5 8 0.76 41 409 0.74 -0.2348

F 0.007 0 F 0.011 0.2348 PB 0.008

114 9/8 5 8 1.92 115 443 0.74 -0.2348

F 0.007 0 F 0.011 0.2348 PB 0.008

115 9/8 5 8A 1.06 59 414 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

116 9/8 5 8A 0.59 30 398 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

117 9/8 5 8A 0.78 42 408 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

118 9/8 5 8A 0.94 51 408 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

119 9/8 5 8A 1.52 88 427 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

120 9/11 5 8A 1.20 68 421 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

121* 9/11 5 8A 3.00 185 - 0.74 -0.2348

F 0.007 0 PB 0.010 0.2348 AF 0.006/0.004

26
Table 6. Final Test 6922 matrix and BLT Tool v.1 flow parameters based on LATCH solutions for models with protuberances (baseline

configuration test results not included). The nominal Mach number is

M = 6 for all test conditions.

Config. Model Reinc/ft Re

∞,1/ft Re

∞,2/ft x/Lref y/Lref Trip

k Reθ/Me k/δ

C Runs per

Type {in.} Config.

1 2 9.75

× 10

5 8.60

× 10

5 1.09

× 10

6 0.10 0 PB 0.008 66.21 0.428 28.31 4

2 2 6.85

× 10

5 5.70

× 10

5 8.00

× 10

5 0.10 0 F (+45

◦

) 0.008 55.84 0.360 20.11 6

1.57

× 10

6 1.50

× 10

6 1.64

× 10

6 0.50 0 PB 0.008 142.68 0.357 50.90

5 3 - - - 0.50 -0.1008 F (+45

◦

) 0.007 - - - 9

- - - 0.50 0.1008

H 0.007 - - -

1.14

× 10

6 1.09

× 10

6 1.18

× 10

6 0.50 0 F (+45

◦

) 0.007 121.86 0.267 32.48

5A 3 - - - 0.50 -0.1008 PB 0.008 - - - 8

- - - 0.50 0.1008

H 0.007 - - -

1.65

× 10

6 1.51

× 10

6 1.78

× 10

6 0.50 0 H 0.007 146.06 0.320 46.67

5B 3 - - - 0.50 -0.1008 PB 0.008 - - - 5

- - - 0.50 0.1008 F (+45

◦

) 0.007 - - -

9.45

× 10

5 8.50

× 10

5 1.04

× 10

6 0.70 0 F (+45

◦

) 0.007 134.35 0.219 29.42

6A 4 7.65

× 10

5 6.80

× 10

5 8.50

× 10

5 0.70 -0.1658 PB 0.008 87.54 0.335 29.30 7

1.65

× 10

6 1.50

× 10

6 1.79

× 10

6 0.70 0.1658

H 0.007 127.43 0.427 54.40

1.15

× 10

6 1.06

× 10

6 1.23

× 10

6 0.70 0 F (90

◦

) 0.007 148.37 0.242 35.84

6B 4 9.55

× 10

5 8.50

× 10

5 1.06

× 10

6 0.70 -0.1658 PB (90

◦

) 0.008 97.23 0.373 36.22 5

1.37

× 10

6 1.23

× 10

6 1.50

× 10

6 0.70 0.1658 AF (90

◦

) 0.006/0.004 116.60 0.335 39.03

2.40

× 10

6 2.23

× 10

6 2.56

× 10

6 0.70 0 F (0

◦

) 0.007 213.22 0.347 74.03

6C 4 9.70

× 10

5 8.60

× 10

5 1.08

× 10

6 0.70 -0.1658 PB (∼ −22.5

◦

) 0.008 98.00 0.375 36.79 6

- - - 0.70 0.1658 AF (0

◦

) 0.006/0.004 - - - 12 6 9.90

× 10

5 9.10

× 10

5 1.07

× 10

6 0.85 0 F (+45

◦

) 0.011 148.85 0.326 48.52 5

12B 6 1.64

× 10

6 1.49

× 10

6 1.79

× 10

6 0.85 0 PB 0.010 191.30 0.381 72.81 5

12A 6 1.37

× 10

6 1.23

× 10

6 1.51

× 10

6 0.85 0 RPB 0.010 175.63 0.349 61.36 5

1.00

× 10

6 9.40

× 10

5 1.06

× 10

6 0.74 0 F (+45

◦

) 0.011 142.79 0.349 49.86

8 5 5.05

× 10

5 4.40

× 10

5 5.70

× 10

5 0.74 -0.2348 F (

−45

◦

) 0.007 57.70 0.367 21.14 6

6.65

× 10

5 5.70

× 10

5 7.60

× 10

5 0.74 0.2348 PB 0.008 66.41 0.482 32.01

1.00

× 10

6 9.40

× 10

5 1.06

× 10

6 0.74 0 PB 0.010 142.79 0.317 45.32

8A 5 8.60

× 10

5 7.80

× 10

5 9.40

× 10

5 0.74 -0.2348 F (+45

◦

) 0.007 75.08 0.478 35.87 6

1.36

× 10

6 1.20

× 10

6 1.52

× 10

6 0.74 0.2348 AF (

−45

◦

) 0.004/0.006 94.72 0.516 48.87

- Transition data not acquired. Total Number of Acceptable Tripped Runs = 77Reinc

=

12

(Re

∞,1 + Re

∞,2)

27
Figure 1. Photograph of a 0.9%-scale Orbiter model installed in the LaRC 20-Inch Mach 6

Air Tunnel.

Figure 2. Sketch of a 0.9%-scale Orbiter model installed in the LaRC 20-Inch Mach 6 Air

Tunnel.

28
1 e

a.

1 e

a. 1 e

a.

M

o

d

el 1

Baseline

M

o

d

el 2

x

/

L

=

0.1

M

o

d

el 3

x

/

L

=

0.5

M

o

d

el 4

x

/

L

=

0.7

1 e

a. 1 e

a.

M

o

d

el 5

x/L=0.74

M

o

d

el 6

x/L=0.85

M

o

d

el 7

R

o

u

g

h

B

a

s

elin

e

1 e

a.

1 e

a.

Figure 3. Windward surface sketch of the 7 models used for Test 6922. Holes to accommodate metal dowels are indicated by the filled bluecircles.

29
"Pizza-Box" Trip

PB

0.0965"

0.060"

k " 521. 0

Adhesive

(Loctite 498)

0.0965" " 0030. 0

" 521. 0

" 500. 0

0.0965"

0.060"

k " 521. 0

Precision

drill rod

"Rounded Pizza-Box" Trip

RPB

0.010-inch

radius

0.0965"

" 521. 0

0.0625"

" 001. 0 Ø 0.0625"

"Hemisphere-type" Trip

H

0.060"

" 0630. 0

" 400. 0

" 330. 0

"Fence" Trip

F

Used for

"angled fence" trip

AF

Figure 4. Schematic of trip-dowel assemblies used as protuberances.

30
Figure 5. Photograph of four typical trip-dowel assemblies used as protuberances are shown above to demonstrate the scale of the trips. The

trip-dowel assemblies shown from left to right are a pizza-box trip, a rounded pizza-box trip, a hemisphere trip, and a fence trip.

31
O

MLDowel

Neodymiummagnet

(1/16" Dia. x 1/32" Thickness)

Bondedw/Loctite498

! to local OML

Figure 6. Schematic depicting a blank dowel inserted into a cast ceramic model to match

OML of surface.

32
Figure 7. Illustration of phosphor thermography acquisition system.

33
Figure 8. Photographic image of model 1 installed in the 20-Inch Mach 6 Air Tunnel.

34
Run 4

Run 1

Run 2

Run 3

Run 5

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Re∞/ft = 0.57 × 106

Re∞/ft = 1.90 × 106

Re∞/ft = 3.74 × 106

Re∞/ft = 4.49 × 106

Re∞/ft = 5.45 × 106

Figure 9. Global aeroheating images for baseline model 1.

35
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R4 w/ M1; Re/ft=0.57× 106

R1 w/ M1; Re/ft=1.90× 106

R2 w/ M1; Re/ft=3.74× 106

R5 w/ M1; Re/ft=4.49× 106

R3 w/ M1; Re/ft=5.45× 106

Figure 10. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for baseline model 1.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 11. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for baseline model 1.

36
Figure 12. Sketch and close-up image of model 2 with a blank dowel installed.

37
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R1 w/ M1; Re/ft=1.90 106

R6 w/ M2; Re/ft=2.08 106

R9 w/ M2; Re/ft=2.08 106

Run 6

Re∞/ft = 2.08 × 106

Figure 13. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 2 with a blank dowel and baseline model 1.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 14. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 2 with a blank dowel and baseline model 1.

38
Figure 15. Close-up image of model 2 with configuration 1.

39
Run 13

Run 11

Run 12

Run 10

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Re∞/ft = 0.86 × 106

Re∞/ft = 1.09 × 106

Re∞/ft = 1.25 × 106

Re∞/ft = 1.78 × 106

Figure 16. Global aeroheating images for model 2 with configuration 1.

40
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R13 w/ M2; Re/ft=0.86× 106

R11 w/ M2; Re/ft=1.09× 106

R12 w/ M2; Re/ft=1.25× 106

R10 w/ M2; Re/ft=1.78× 106

Figure 17. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 2 with configuration 1.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 18. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 2 with configuration 1.

41
Figure 19. Close-up image of model 2 with configuration 2. Clockwise rotation of fence

relative to model centerline is denoted as positive angle.

42
Run 19

Run 17

Run 16

Run 15

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 20

Run 14

Re∞/ft = 0.45 × 106

Re∞/ft = 0.57 × 106

Re∞/ft = 0.80 × 106

Re∞/ft = 1.06 × 106

Re∞/ft = 1.25 × 106

Re∞/ft = 1.77 × 106

Figure 20. Global aeroheating images for model 2 with configuration 2.

43
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R19 w/ M2; Re/ft=0.45× 106

R17 w/ M2; Re/ft=0.57× 106

R16 w/ M2; Re/ft=0.80× 106

R15 w/ M2; Re/ft=1.06× 106

R20 w/ M2; Re/ft=1.25× 106

R14 w/ M2; Re/ft=1.77× 106

Figure 21. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 2 with configuration 2.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 22. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 2 with configuration 2.

44
Figure 23. Sketch and close-up image of model 3 with three blank dowels installed.

45
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R1 w/ M1; Re/ft=1.90× 106

R2 w/ M1; Re/ft=3.74× 106

R21 w/ M3; Re/ft=1.89× 106

R22 w/ M3; Re/ft=3.71× 106

Figure 24. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with three blank dowels and baseline model 1.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 25. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with three blank dowels and baseline model 1.

46
Figure 26. Close-up image of model 3 with configuration 5. Clockwise rotation of fence

relative to model centerline is denoted as positive angle.

47
Run 28

Run 29

Run 30

Run 32

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 25

Run 26

Re∞/ft = 1.07 × 106

Re∞/ft = 1.22 × 106

Re∞/ft = 1.50 × 106

Re∞/ft = 1.64 × 106

Re∞/ft = 1.76 × 106

Re∞/ft = 2.07 × 106

Figure 27. Global aeroheating images for model 3 with configuration 5.

48
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R28 w/ M3; Re/ft=1.07× 106

R29 w/ M3; Re/ft=1.22× 106

R30 w/ M3; Re/ft=1.50× 106

R32 w/ M3; Re/ft=1.64× 106

R25 w/ M3; Re/ft=1.76× 106

R26 w/ M3; Re/ft=2.07× 106

R27 w/ M3; Re/ft=2.50× 106

R31 w/ M3; Re/ft=3.06× 106

R33 w/ M3; Re/ft=3.43× 106

Figure 28. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with configuration 5.

!!"# !!"$ ! !"$ !"# !

!"!%

!"&

!"&%

!"$

!"$%

!"'

!"'%

!"#

()L+e-

.).+e-

/)L+e-0!"1!!!

Figure 29. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with configuration 5.

49
Figure 30. Close-up image of model 3 with configuration 5A. Clockwise rotation of fence

relative to model centerline is denoted as positive angle.

50
Run 36

Run 41

Run 37

Run 35

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 34

Run 39

Re∞/ft = 1.09 × 106

Re∞/ft = 1.18 × 106

Re∞/ft = 1.23 × 106

Re∞/ft = 1.49 × 106

Re∞/ft = 2.06 × 106

Re∞/ft = 2.55 × 106

Figure 31. Global aeroheating images for model 3 with configuration 5A.

51
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R36 w/ M3; Re/ft=1.09× 106

R41 w/ M3; Re/ft=1.18× 106

R37 w/ M3; Re/ft=1.23× 106

R35 w/ M3; Re/ft=1.49× 106

R34 w/ M3; Re/ft=2.06× 106

R39 w/ M3; Re/ft=2.55× 106

R38 w/ M3; Re/ft=3.01× 106

R40 w/ M3; Re/ft=3.38× 106

Figure 32. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with configuration 5A.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 33. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with configuration 5A.

52
Figure 34. Close-up image of model 3 with configuration 5B. Clockwise rotation of fence

relative to model centerline is denoted as positive angle.

53
Run 44

Run 42

Run 43

Run 45

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 46

Re∞/ft = 1.23 × 106

Re∞/ft = 1.51 × 106

Re∞/ft = 1.78 × 106

Re∞/ft = 2.10 × 106

Re∞/ft = 2.56 × 106

Figure 35. Global aeroheating images for model 3 with configuration 5B.

54
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R44 w/ M3; Re/ft=1.23× 106

R42 w/ M3; Re/ft=1.51× 106

R43 w/ M3; Re/ft=1.78× 106

R45 w/ M3; Re/ft=2.10× 106

R46 w/ M3; Re/ft=2.56× 106

Figure 36. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 3 with configuration 5B.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 37. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 3 with configuration 5B.

55
Figure 38. Close-up image of model 4 with three blank dowels installed.

56
Run 53

Run 51

Run 52

Run 55

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 50

Run 49

x

x

x

Re∞/ft = 1.08 × 106

Re∞/ft = 2.07 × 106

Re∞/ft = 2.55 × 106

Re∞/ft = 3.05 × 106

Re∞/ft = 4.49 × 106

Re∞/ft = 3.75 × 106

Figure 39. Global aeroheating images for model 4 with three blank dowels.

57
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R53 w/ M4; Re/ft=1.08× 106

R51 w/ M4; Re/ft=2.07× 106

R52 w/ M4; Re/ft=2.55× 106

R55 w/ M4; Re/ft=3.05× 106

R48 w/ M4; Re/ft=3.70× 106

R50 w/ M4; Re/ft=3.75× 106

R49 w/ M4; Re/ft=4.49× 106

Figure 40. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with three blank dowels.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.8000

Figure 41. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.8

for model 4 with three blank dowels

58
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R1 w/ M1; Re/ft=1.90× 106

R2 w/ M1; Re/ft=3.74× 106

R5 w/ M1; Re/ft=4.49× 106

R51 w/ M4; Re/ft=2.07× 106

R50 w/ M4; Re/ft=3.75× 106

R49 w/ M4; Re/ft=4.49× 106

Figure 42. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with three blank dowels and baseline model 1.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.8000

Figure 43. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.8

for model 4 with three blank dowels and baseline model 1.

59
Figure 44. Close-up image of model 4 with configuration 6A. Clockwise rotation of fence

relative to model centerline is denoted as positive angle.

60
Run 57

Run 58

Run 56

Run 61

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 60

Run 63

Re∞/ft = 0.68 × 106

Re∞/ft = 0.85 × 106

Re∞/ft = 1.04 × 106

Re∞/ft = 1.50 × 106

Re∞/ft = 1.79 × 106

Re∞/ft = 2.06 × 106

Figure 45. Global aeroheating images for model 4 with configuration 6A.

61
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R57 w/ M4; Re/ft=0.68× 106

R58 w/ M4; Re/ft=0.85× 106

R56 w/ M4; Re/ft=1.04× 106

R62 w/ M4; Re/ft=1.22× 106

R61 w/ M4; Re/ft=1.50× 106

R60 w/ M4; Re/ft=1.79× 106

R63 w/ M4; Re/ft=2.06× 106

Figure 46. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with configuration 6A.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 47. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 4 with configuration 6A.

62
Figure 48. Close-up image of model 4 with configuration 6B. Diagonal of PB trip is at 45◦

from model centerline.

63
Run 66

Run 64

Run 67

Run 65

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 68

Re∞/ft = 0.85 × 106

Re∞/ft = 1.06 × 106

Re∞/ft = 1.23 × 106

Re∞/ft = 1.50 × 106

Re∞/ft = 1.79 × 106

Figure 49. Global aeroheating images for model 4 with configuration 6B.

64
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R66 w/ M4; Re/ft=0.85× 106

R64 w/ M4; Re/ft=1.06× 106

R67 w/ M4; Re/ft=1.23× 106

R65 w/ M4; Re/ft=1.50× 106

R68 w/ M4; Re/ft=1.79× 106

Figure 50. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with configuration 6B.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 51. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 4 with configuration 6B.

65
Figure 52. Close-up image of model 4 with configuration 6C. Diagonal of PB trip is approximately −22.5

◦

from model centerline.

66
Run 71

Run 70

Run 69

Run 74

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 72

Run 73

Re∞/ft = 0.86 × 106

Re∞/ft = 1.08 × 106

Re∞/ft = 1.79 × 106

Re∞/ft = 2.23 × 106

Re∞/ft = 2.56 × 106

Re∞/ft = 3.04 × 106

Figure 53. Global aeroheating images for model 4 with configuration 6C.

67
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R71 w/ M4; Re/ft=0.86× 106

R70 w/ M4; Re/ft=1.08× 106

R69 w/ M4; Re/ft=1.79× 106

R74 w/ M4; Re/ft=2.23× 106

R72 w/ M4; Re/ft=2.56× 106

R73 w/ M4; Re/ft=3.04× 106

Figure 54. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 4 with configuration 6C.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 55. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 4 with configuration 6C.

68
Figure 56. Close-up image of model 6 with a blank dowel installed.

69
Run 76

Run 75

Run 77

Run 78

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 79

x

Re∞/ft = 1.92 × 106

Re∞/ft = 3.04 × 106

Re∞/ft = 3.80 × 106

Re∞/ft = 4.50 × 106

Re∞/ft = 5.41 × 106

Figure 57. Global aeroheating images for model 6 with a blank dowel.

70
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R76 w/ M6; Re/ft=1.92× 106

R75 w/ M6; Re/ft=3.04× 106

R77 w/ M6; Re/ft=3.80× 106

R78 w/ M6; Re/ft=4.50× 106

R79 w/ M6; Re/ft=5.41× 106

Figure 58. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with a blank dowel.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

./.ref

x/Lref=0.9000

Figure 59. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with a blank dowel.

71
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R1 w/ M1; Re/ft=1.90× 106

R2 w/ M1; Re/ft=3.74× 106

R5 w/ M1; Re/ft=4.49× 106

R3 w/ M1; Re/ft=5.45× 106

R76 w/ M6; Re/ft=1.92× 106

R77 w/ M6; Re/ft=3.80× 106

R78 w/ M6; Re/ft=4.50× 106

R79 w/ M6; Re/ft=5.41× 106

Figure 60. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with a blank dowel and baseline model 1.

!!"# !!"$ ! !"$ !"# !

!"!%

!"&

!"&%

!"$

!"$%

!"'

!"'%

!"#

()L+e-

.).+e-

/)L+e-0!"1!!!

Figure 61. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.8

for model 6 with a blank dowel and baseline model 1.

72
Figure 62. Close-up image of model 6 with configuration 12.

73
Run 85

Run 83

Run 81

Run 84

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 86

Re∞/ft = 0.77 × 106

Re∞/ft = 1.07 × 106

Re∞/ft = 0.91 × 106

Re∞/ft = 1.50 × 106

Re∞/ft = 1.78 × 106

Figure 63. Global aeroheating images for model 6 with configuration 12.

74
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R85 w/ M6; Re/ft=0.77× 106

R83 w/ M6; Re/ft=0.91× 106

R81 w/ M6; Re/ft=1.07× 106

R84 w/ M6; Re/ft=1.50× 106

R86 w/ M6; Re/ft=1.78× 106

Figure 64. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with configuration 12.

!!"# !!"$ ! !"$ !"# !

!"!%

!"&

!"&%

!"$

!"$%

!"'

!"'%

!"#

()*+,-

.).+,-

/)*+,-0!"1!!!

Figure 65. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with configuration 12.

75
Figure 66. Close-up image of model 6 with configuration 12B.

76
Run 87

Run 88

Run 91

Run 90

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 92

Re∞/ft = 1.06 × 106

Re∞/ft = 1.49 × 106

Re∞/ft = 1.79 × 106

Re∞/ft = 2.07 × 106

Re∞/ft = 2.31 × 106

Figure 67. Global aeroheating images for model 6 with configuration 12B.

77
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R87 w/ M6; Re/ft=1.06× 106

R88 w/ M6; Re/ft=1.49× 106

R91 w/ M6; Re/ft=1.79× 106

R90 w/ M6; Re/ft=2.07× 106

R92 w/ M6; Re/ft=2.31× 106

Figure 68. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with configuration 12B.

!0.# !0.2 0 0.2 0.# 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.#

(/L+e-

./.+ex/L+e-=0.9000

Figure 69. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with configuration 12B.

78
Figure 70. Close-up image of model 6 with configuration 12A.

79
Run 93

Run 95

Run 96

Run 94

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 97

Re∞/ft = 1.07 × 106

Re∞/ft = 1.23 × 106

Re∞/ft = 1.51 × 106

Re∞/ft = 1.78 × 106

Re∞/ft = 2.08 × 106

Figure 71. Global aeroheating images for model 6 with configuration 12A.

80
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R93 w/ M6; Re/ft=1.07× 106

R95 w/ M6; Re/ft=1.23× 106

R96 w/ M6; Re/ft=1.51× 106

R94 w/ M6; Re/ft=1.78× 106

R97 w/ M6; Re/ft=2.08× 106

Figure 72. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 6 with configuration 12A.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 73. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 6 with configuration 12A.

81
Figure 74. Photographic image of model 7 installed in the 20-Inch Mach 6 Air Tunnel.

82
Run 101

Run 100

Run 103

Run 99

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 104

Re∞/ft = 0.59 × 106

Re∞/ft = 1.92 × 106

Re∞/ft = 3.03 × 106

Re∞/ft = 3.78 × 106

Re∞/ft = 4.51 × 106

Figure 75. Global aeroheating images for baseline model 7.

83
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R101 w/ M7; Re/ft=0.59× 106

R100 w/ M7; Re/ft=1.92× 106

R103 w/ M7; Re/ft=3.03× 106

R99 w/ M7; Re/ft=3.78× 106

R104 w/ M7; Re/ft=4.51× 106

Figure 76. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for baseline model 7.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 77. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for baseline model 7.

84
Run 1

Run 2

Run 5

Run 99

Run 100

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Model #1 Model #7

Run 104

Re∞/ft = 1.90 × 106

Re∞/ft = 3.74 × 106

Re∞/ft = 4.49 × 106

Re∞/ft = 1.92 × 106

Re∞/ft = 3.78 × 106

Re∞/ft = 4.51 × 106

Figure 78. Global aeroheating images for baseline model 7 and baseline model 1.

85
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R1 w/ M1; Re/ft=1.90× 106

R2 w/ M1; Re/ft=3.74× 106

R5 w/ M1; Re/ft=4.49× 106

R3 w/ M1; Re/ft=5.45× 106

R100 w/ M7; Re/ft=1.92× 106

R99 w/ M7; Re/ft=3.78× 106

R104 w/ M7; Re/ft=4.51× 106

Figure 79. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for baseline model 7 and baseline model 1.

86
Figure 80. Sketch and close-up image of model 5 with three blank dowels installed.

87
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R1 w/ M1; Re/ft=1.90× 106

R105 w/ M5; Re/ft=2.07× 106

R108 w/ M5; Re/ft=2.54× 106

Figure 81. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 5 with three blank dowels and baseline model 1.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 82. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 5 with three blank dowels and baseline model 1.

88
Figure 83. Close-up image of model 5 with configuration 8.

89
Run 112

Run 111

Run 113

Run 110

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 109

Run 114

Re∞/ft = 0.44 × 106

Re∞/ft = 0.57 × 106

Re∞/ft = 0.76 × 106

Re∞/ft = 0.94 × 106

Re∞/ft = 1.06 × 106

Re∞/ft = 1.92 × 106

Figure 84. Global aeroheating images for model 5 with configuration 8.

90
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R112 w/ M5; Re/ft=0.44× 106

R111 w/ M5; Re/ft=0.57× 106

R113 w/ M5; Re/ft=0.76× 106

R110 w/ M5; Re/ft=0.94× 106

R109 w/ M5; Re/ft=1.06× 106

R114 w/ M5; Re/ft=1.92× 106

Figure 85. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 5 with configuration 8.

!0.4 !0.2 0 0.2 0.4 0

0.0%

0.1

0.1%

0.2

0.2%

0.3

0.3%

0.4

(/L+eh/h+ex/L+e-=0.1000

Figure 86. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 5 with configuration 8.

91
Figure 87. Close-up image of model 5 with configuration 8A.

92
Run 116

Run 117

Run 118

Run 115

0.0 0.1 0.2 0.3 0.4 0.5

h/h r ef

Run 120

Run 119

Re∞/ft = 0.59 × 106

Re∞/ft = 0.78 × 106

Re∞/ft = 0.94 × 106

Re∞/ft = 1.06 × 106

Re∞/ft = 1.20 × 106

Re∞/ft = 1.52 × 106

Figure 88. Global aeroheating images for model 5 with configuration 8A.

93
0 0.2 0.4 0.6 0.8 1

0

0.1

0.2

0.3

0.4

0.5

x/Lref

h/href

y/Lref=0

R116 w/ M5; Re/ft=0.59× 106

R117 w/ M5; Re/ft=0.78× 106

R118 w/ M5; Re/ft=0.94× 106

R115 w/ M5; Re/ft=1.06× 106

R120 w/ M5; Re/ft=1.20× 106

R119 w/ M5; Re/ft=1.52× 106

Figure 89. Streamwise line cuts of normalized heat-transfer measurements at y/Lref = 0

for model 5 with configuration 8A.

!0.4 !0.2 0 0.2 0.4 0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

y/Lref

h/href

x/Lref=0.9000

Figure 90. Spanwise line cuts of normalized heat-transfer measurements at x/Lref = 0.9

for model 5 with configuration 8A.

94
10

100

0.1 1.0

Mach 6-Existing Data

Mach 6-TEI Data

c=27 ( = Re/M

e

x k/)

c=33

c=50

Re

/M

e

k/

Figure 91. Comparison of existing Mach 6 data and newly acquired TEI data in the parameter space of the BLT Tool v.1.

95
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704–0188

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Prescribed by ANSI Std. Z39.18

1. REPORT DATE (DD-MM-YYYY)

01-02-2008

2. REPORT TYPE

Technical Memorandum

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Effect of Protuberance Shape and Orientation on Space Shuttle Orbiter

Boundary-Layer Transition

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

377816.06.03.03.08

6. AUTHOR(S)

Rudolph A. King, Scott A. Berry, Michael A. Kegerise

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center

Hampton, Virginia 23681-2199

8. PERFORMING ORGANIZATION

REPORT NUMBER

L–19425

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

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NASA

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NUMBER(S)

NASA/TM–2008–215103

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified-Unlimited

Subject Category 34

Availability: NASA CASI (301) 621-0390

13. SUPPLEMENTARY NOTES

An electronic version can be found at http://ntrs.nasa.gov.

14. ABSTRACT

This document describes an experimental study conducted to examine the effects of protuberances on hypersonic boundary-layer

transition. The experiment was conducted in the Langley 20-Inch Mach 6 Tunnel on a series of 0.9%-scale Shuttle Orbiter models. The

data were acquired to complement the existing ground-based boundary-layer transition database that was used to develop Version 1.0 of

the boundary-layer transition RTF (return-to-flight) tool. The existing ground-based data were all acquired on 0.75%-scale Orbiter

models using diamond-shaped (“pizza-box”) trips. The larger model scale facilitated in manufacturing higher fidelity protuberances.

The end use of this experimental database will be to develop a technical basis (in the form of a boundary-layer transition correlation) to

assess representative protrusion shapes, e.g., gap fillers and protrusions resulting from possible tile repair concepts. The primary

objective of this study is to investigate the effects of protuberance-trip location and geometry on Shuttle Orbiter boundary-layer

transition. Secondary goals are to assess the effects of gap-filler orientation and other protrusion shapes on boundary-layer transition.

Global heat-transfer images using phosphor thermography of the Orbiter windward surface and the corresponding streamwise and

spanwise heating distributions were used to infer the state of the boundary layer, i.e., laminar, transitional, or turbulent.

15. SUBJECT TERMS

boundary layer, transition, aeroheating, hypersonic, Orbiter

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100

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STI Help Desk (email: help@sti.nasa.gov)

19b. TELEPHONE NUMBER (Include area code)

(301) 621-0390