bluuebunny/crossref_metadata_2025 huggingface dataset:
Viscous Interaction Upstream and Downstream of a Turbine Stator Cascade With a Periodic Wake Field
Authors: McFarland Vernon E. , Tiederman William G.
Published: March 2015

The influence of periodic rotor wakes has a substantial effect on the flow in a turbine stator cascade. A mechanism located upstream of a linear, low-aspect ratio, turbine cascade simulated wakes shed from rotor blades by translating cylindrical rods across the inlet of the cascade. In order to provide a test case to increase our fundamental understanding of the unsteady viscous flow typical of a gas turbine engine, three components of velocity, phase-locked into sixteen time windows which encompassed the rotor period, were measured at two upstream planes and one downstream plane. Due to the effects in the endwall region, the wake in the inlet plane bows in the tangential direction as the wake translates into the passage. The effects of the passage vortex do not decay significantly within one chord downstream of the exit of the cascade. The location of the passage vortex at the far downstream exit plane is dependent upon rotor position, as reported in earlier studies. A complete data set of the mean and fluctuating velocity components at all sixteen time windows is available on diskette.
Three-Dimensional Flow Phenomena in a Transonic, High-Through-Flow, Axial-Flow Compressor Stage
Authors: Copenhaver William W. , Hah Chunill , Puterbaugh Steven L.
Published: March 2015

A detailed aerodynamic study of a transonic, high-through-flow, single stage compressor is presented. The compressor stage was comprised of a low-aspect-ratio rotor combined alternately with two different stator designs. Both experimental and numerical studies are conducted to understand the details of the complex flow field present in this stage. Aerodynamic measurements using high-frequency, Kulite pressure transducers and conventional probes are compared with results from a three-dimensional viscous flow analysis. A steady multiple blade row approach is used in the numerical technique to examine the detailed flow structure inside the rotor and the stator passages. The comparisons indicate that many flow field features are correctly captured by viscous flow analysis, and therefore unmeasured phenomena can be studied with some level of confidence.
Experimental Study on the Flow Characteristics of Streamwise Inclined Jets in Crossflow on Flat Plate
Authors: Lee Sang Woo , Lee Joon Sik , Ro Sung Tack
Published: March 2015

Experimental study has been conducted to investigate the flow characteristics of streamwise 35° inclined jets, injected into a turbulent crossflow boundary layer on a flat plate. Flow is visualized by schlieren photographs for both normal and inclined jets to determine the overall flow structure with the variation of the velocity ratio. Three-dimensional velocity field is measured for two velocity ratios of 1.0 and 2.0 by using a five-hole directional probe. The visualization study shows that a slight variation of the injection angle produces a significant change in the flow structure. It is recognized that the jet flow is mainly dominated by the turbulence for a small velocity ratio, but it is likely to be influenced by an inviscid vorticity dynamics for a large velocity ratio. Such a trend prevails in the streamwise inclined injection, compared with the normal injection. A pair of bound vortices accompanied with a complex three-dimensional flow is present in the downstream region of the jet exit as in the case of the normal injection, although its magnitude and range are different, and the strength of the bound vortex is strongly dependent on the velocity ratio. The interface between the jet and the crossflow is identified from the vorticity distribution.
Low Aspect Ratio Transonic Rotors: Part 1 — Baseline Design and Performance
Authors: Law C. H. , Wadia A. R.
Published: March 2015

The analytical design and experimental test of a single-stage transonic axial-flow compressor are described. This design is the baseline of a compressor design study in which several blade design parameters have been systematically varied to determine their independent effects on compressor performance. The baseline design consisted of ruggedizing an existing compressor design, that demonstrated outstanding aerodynamic performance, to correct some undesirable aeromechanical characteristics. The design study was performed by varying only one design parameter at a time, keeping other design variables as close as possible to the baseline design. Specific design parameters of interest were those for which very little data was available to determine their sensitivity on compressor performance. This paper describes the baseline compressor design and its experimental performance. A detailed definition and flow analysis of the baseline design test point (used as the basis for all subsequent design variations) are provided.
Heat Transfer in Rotating Serpentine Passages With Trips Skewed to the Flow
Authors: Johnson B. V. , Wagner J. H. , Steuber G. D. , Yeh F. C.
Published: March 2015

Experiments were conducted to determine the effects of buoyancy and Coriolis forces on heat transfer in turbine blade internal coolant passages. The experiments were conducted with a large scale, multi-pass, heat transfer model with both radially inward and outward flow. Trip strips, skewed at 45 degrees to the flow direction, were machined on the leading and trailing surfaces of the radial coolant passages. An analysis of the governing flow equations showed that four parameters influence the heat transfer in rotating passages: coolant-to-wall temperature ratio, rotation number, Reynolds number and radius-to-passage hydraulic diameter ratio. The first three of these four parameters were varied over ranges which are typical of advanced gas turbine engine operating conditions. Results were correlated and compared to previous results from similar stationary and rotating models with smooth walls and with trip strips normal to the flow direction. The heat transfer coefficients on surfaces, where the heat transfer decreased with rotation and buoyancy, decreased to as low as 40 percent of the value without rotation. However, the maximum values of the heat transfer coefficients with high rotation were only slightly above the highest levels previously obtained with the smooth wall model. It was concluded that (1) both Coriolis and buoyancy effects must be considered in turbine blade cooling designs with trip strips, (2) the effects of rotation are markedly different depending upon the flow direction and (3) the heat transfer with skewed trip strips is less sensitivity to buoyancy than the heat transfer in models with either smooth walls or normal trips. Therefore, skewed trip strips rather than normal trip strips are recommended and geometry-specific tests will be required for accurate design information.
The Solution-Adaptive Numerical Simulation of the 3D Viscous Flow in the Serpentine Coolant Passage of a Radial Inflow Turbine Blade
Authors: Dawes W. N.
Published: March 2015

This paper describes the application of a solution-adaptive, three dimensional Navier-Stokes solver to the problem of the flow in turbine internal coolant passages. First the variation of Nusselt number in a cylindrical, multi-ribbed duct is predicted and found to be in acceptable agreement with experimental data. Then the flow is computed in the serpentine coolant passage of a radial inflow turbine including modelling the internal baffles and pin fins. The aerodynamics of the passage, particularly that associated with the pin fins, is found to be complex. The predicted heat transfer coefficients allow zones of poor coolant penetration and potential hot spots to be identified.
Wake-Induced Unsteady Stagnation-Region Heat-Transfer Measurements
Authors: Magari P. J. , LaGraff L. E.
Published: March 2015

An experimental investigation of wake-induced unsteady heat transfer in the stagnation region of a cylinder was conducted. The objective of the study was to create a quasi-steady representation of the stator/rotor interaction in a gas turbine using two stationary cylinders in crossflow. In this simulation, a larger cylinder, representing the leading-edge region of a rotor blade, was immersed in the wake of a smaller cylinder, represenung the trailing-edge region of a stator vane. Time-averaged and time-resolved heat-transfer results were obtained over a wide range of Reynolds numbers at two Mach numbers: one incompressible and one transonic. The tests were conducted at Reynolds numbers, Mach numbers and gas-to-wall temperature ratios characteristic of turbine engine conditions in an isentropic compression-heated transient wind tunnel (LICH tube). The augmentation of the heat transfer in the stagnation region due to wake unsteadiness was documented by comparison with isolated cylinder tests. It was found that the time-averaged heat-transfer rate at the stagnation line, expressed in terms of the Frossling number (Nu/√Re), reached a maximum independent of the Reynolds number. The power spectra and cross correlation of the heat-transfer signals in the stagnation region revealed the importance of large vortical structures shed from the upstream wake generator. These structures caused large positive and negative excursions about the mean heat-transfer rate in the stagnation region.
The Effect of a Turbulent Wake on the Stagnation Point: Part II — Heat Transfer Results
Authors: Hanford Anthony J. , Wilson Dennis E.
Published: March 2015

A phenomenological model is proposed which relates the effects of freestream turbulence to the increase in stagnation point heat transfer. The model requires both turbulence intensity and energy spectra as inputs to the unsteady velocity at the edge of the boundary layer. The form of the edge velocity contains both a pulsation of the incoming flow and an oscillation of the streamlines. The incompressible unsteady and time-averaged boundary layer response is determined by solving the momentum and energy equations. The model allows for arbitrary two-dimensional geometry, however, results are given only for a circular cylinder. The time-averaged Nusselt number is determined theoretically and compared to existing experimental data.
Heat Transfer on a Flat Surface Under a Region of Turbulent Separation
Authors: Rivir R. B. , Johnston J. P. , Eaton J. K.
Published: March 2015

Fluid dynamics and heat transfer measurements were performed for a separation bubble formed on a smooth, flat, constant-heat-flux plate. The separation was induced by an adverse pressure gradient created by deflection of the opposite wall of the wind tunnel. The heat transfer rate was found to decline monotonically approaching the separation point and reach a broad minimum approximately 60% below zero-pressure-gradient levels. The heat transfer rate increased rapidly approaching reattachment with a peak occuring slightly downstream of the mean reattachment point. The opposite wall shape was varied to reduce the applied adverse pressure gradient. The heat transfer results were similar as long as the pressure gradient was sufficient to cause full separation of the boundary layer.
Comparison of Spectrometric Techniques for the Analysis of Liquid Gas Turbine Fuels
Authors: Lukas Malte
Published: March 2015

High temperature corrosion and fuel system fouling are major concerns that confront gas turbine users. Fuel treatment is a critical requirement for gas turbine operators burning alternative fuels and even so called “clean fuels”. Spectrometric fuel analysis is used to determine the amount of treatment required as well as the efficiency of the treatment. In most cases, analytical techniques developed by chemists for use in laboratory environments have been adopted for field use.

This paper describes the various spectrometric techniques available to the gas turbine user to analyze fuels for contaminants such as sodium, potassium, vanadium, lead, calcium, silicon etc. and additives such as magnesium compounds. Atomic absorption spectroscopy (AAS) and various atomic emission spectroscopy (AES) techniques will be discussed and compared.
Hypersonic Flow Separation in Shock Wave Boundary Layer Interactions
Authors: Hamed A. , Kumar Ajay
Published: March 2015

This work presents an assessment of the experimental data on separated flow in shock wave turbulent boundary layer interactions at hypersonic and supersonic speeds. The data base consist of selected configurations where the only characteristic length in the interation is the incoming boundary layer thickness. It consists of two dimensional and axisymmetric interactions in compression corners or cylinder-flares, and externally generated oblique shock interactions with boundary layers over flat plates or cylindrical surfaces. The conditions leading to flow separation and the empirical correlations for incipient separation are reviewed. The effects of Mach number, Reynolds number, surface cooling and the methods of detecting separation are discussed.
The Measurement and Prediction of the Tip Clearance Flow in Linear Turbine Cascades
Authors: Heyes F. J. G. , Hodson H. P.
Published: March 2015

This paper describes a simple two-dimensional model for the calculation of the leakage flow over the blade tips of axial turbines. The results obtained from calculations are compared with data obtained from experimental studies of two linear turbine cascades. One of these cascades has been investigated by the authors and previously unpublished experimental data is provided for comparison with the model. In each of the test cases examined, excellent agreement is obtained between the experimental and predicted data. Although ignored in the past, the importance of pressure gradients along the blade chord is highlighted as a major factor influencing the tip leakage flow.
Flutter of Grouped Turbine Blades
Authors: Whitehead D. S. , Evans D. H.
Published: March 2015

An analysis is presented to predict flutter in a wheel of turbine blades which are connected together into a number of identical groups. The natural frequencies and mode shapes of a group are assumed to be known. The unsteady aerodynamic coefficients for free-standing blades are assumed to be known from an unsteady aerodynamic program, and FINSUP is used here. The work fed into the vibration by the aerodynamic forces is then calculated.

This is illustrated by two examples of low pressure steam turbine blade rows GR-1 and GR-2. On GR-1 the three modes considered are all found to be stable, but on GR-2 the lowest frequency mode shows some instability. Tying the blades together in groups is found to be stabilizing.

Blade response, measured by a Blade Vibration Monitor at two different installations, is shown for a range of operating conditions. The measured responses indicate the GR-1 blade is stable whereas the GR-2 blade shows, at the lowest frequency, high response that is dependent on turbine operating conditions.
Embedded Microprocessor Digital Control for Vehicular Turbine Management System
Authors: Kundra Manju , Bluish Joe
Published: March 2015

A microprocessor-based engine controller was developed for the M1A1 battle tank’s Textron Lycoming AGT1500 Gas Turbine Engine. A discussion of production (Block I) and future generation (Block II) Digital Electronic Control is first given to show their evolution. The design includes many unique adaptive features: fault storage, software downloading by serial communication (RS232 or MIL-STD-1553), back-up battery, Real Time Clock, protective modes, diagnostic and health monitoring, etc. Additional features address reliability, maintainability, interchangeability, and a hostile nuclear environment; including radiated susceptibility, nuclear radiation, etc. Detailed discussion is included of functional architecture, hardware implementation and design considerations such as: CPU (Central Processing Unit) and associated circuitry design, signal processing, Analog/Digital and Digital/Analog conversion, and software Standards, Procedure, and Methodology. A brief discussion of a future enhancement feature, a Diagnostic Memory Unit for history recording and storage via RS232 data bus, is included in this paper.
Design and Test of a Low-NOx Advanced Rich-Lean Combustor for LBG Fueled 1300°C-Class Gas Turbine
Authors: Nakata T. , Sato M. , Ninomiya T. , Yoshine T. , Yamada M.
Published: March 2015

Research and development of an IGCC (Integrated Coal Gasification Combined Cycle) power generation system is being carried out as one of the advanced coal utilization technology in Japan. The coal gasified fuel, which is produced in a coal gasifier of air-blown entrained-flow type has calorific value as low as 1/10 of LNG. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. The authors have designed and made an 1300°C-class advanced rich-lean combustor mainly designed for achieving low fuel-NOx combustion. By testing it under atmospheric pressure conditions, we have successfully reduced the NOx emissions (to 60 ppm corrected at 16 percent O2) by more than half the level previously achieved when the ammonia concentration was 1000 ppm. Combustion stability was adequate even when the calorific value of the fuel decreased to 2700 kJ/m3N.
Internal Cooling Passage Heat Transfer Near the Entrance to a Film Cooling Hole: Experimental and Computational Results
Authors: Byerley A. R. , Jones T. V. , Ireland P. T.
Published: March 2015

Detailed heat transfer measurements were made near the entrance to a single film cooling hole using a transient liquid crystal technique in a large scale (100X) model. The hole inclination angle and flow extraction rate were varied across a range representative of actual engine conditions. Local values of heat transfer were found to exceed 6 times the levels associated with fully developed, turbulent channel flow. The region of maximum heat transfer enhancement occurred downstream of the hole entrance. Computational and experimental flow diagnostics were performed to investigate the mechanisms responsible for the observed heat transfer distributions. The removal of the upstream boundary layer and the downwash created by a vortex pair were found to be important phenomena.
Flow Characteristics of a 35° Inclined Turbulent Jet in a Crossflow on a Concave Surface
Authors: Lee Sang Woo , Lee Joon Sik , Lee Taik Sik
Published: March 2015

The effect of the concave curvature on the flow of a streamwise 35° inclined jet issuing into a crossflow boundary layer has been investigated experimentally. Three-dimensional velocity measurements are performed in the near-field and some downstream region of jet exit by using a 5-hole directional probe. Since the main purpose is to investigate solely the effect of the concave curvature, the upper wall of the curved region is adjusted to minimize the effect of the streamwise pressure gradient. The results show that in the vicinity of the jet exit, the bound vortex dominates the flow structure, while in the far downstream region, the concave curvature plays an important role in converting the secondary flow into the Taylor-Görtler type flow. In addition, vortices rotating in the opposite direction with respect to the bound vortex is generated at both sides of the bound vortices, which stimulate the mixing of the jet and crossflow fluid. When the velocity ratio is large, the horseshoe vortex exists in the neighborhood of the jet exit, even though the strength is very weak compared with the bound vortex, however this horseshoe vortex may act as a kind of steady disturbance on the concave surface.
Navier-Stokes Computation on a Pivoting Doors Thrust Reverser and Comparison With Tests
Authors: Schreiber L. , Legras M.
Published: March 2015

An engine thrust reverser must meet different aerodynamic requirements to take into account the engine and airplane integration.

These requirements are:

- Control of the exit area in order to assess a convenient engine compatibility during the reverser operation.

- Generation of reverse thrust meeting the level specified by the airframe in order to slowdown the airplane.

- Mimization of the reversed flow field interaction with the airplane structure such as wing and shutters.

- Avoid the flow reingestion by the engine fan.

In order to reduce the tests number, to decrease the development delay and to improve aerodynamic performance, SNECMA group (SNECMA and HISPANO-SUIZA) has decided to develop a CFD method adapted to pivoting doors thrust reverser aerodynamic calculation.

This method uses a Navier-Stokes 3D solver (PHOENICS code) well adapted to complex geometry and complex flow field. The mesh is generated with an analytical method and only one domain is used. The computation has been completed assuming laminar viscosity.

The numerical data got with this method have been compared to static test realized on a model similar to actual CFM56-5C four doors reverser. The comparison parameters are the static pressure on the doors, the flow rate and the axial reverse thrust.
Development of an Indirect Coal-Fired High Performance Power Generation System
Authors: Bannister R. L. , Amos D. J. , Scalzo A. J. , Datsko S. C.
Published: March 2015

The U.S. Department of Energy/Pittsburgh Energy Technology Center (DOE/PETC) initiated the Engineering Development of Coal-Fired High Performance Power Generation Systems Program to develop an advanced technology for coal-fired electric plants that can boost efficiency and reduce emissions. This three phase program includes concept definition and preliminary R&D, engineering development and testing which will culminate in the operation of a prototype plant by the year 2005.

This paper presents an overview of the work proposed by a Westinghouse-led R&D team which includes Babcock and Wilcox, Black and Veatch, FluiDyne Engineering, and Allegheny Power Systems to design and evaluate the technical and economic feasibility and relevant R&D required for one or more advanced power generation concepts developed during Phase I. Allison Division of General Motors, ERC and SeiTec are also supporting the Westinghouse team in the initial phase of this program.

Key objectives include evaluation of plant cycle designs capable of at least 47-percent efficiency, substantial reductions in airborne emissions below current new source performance standards (NSPS) for coal-fired boilers, and solid waste generation of only benign material.

The proposed design approach includes an indirect coal-fired combustion turbine combined cycle system which incorporates a high-temperature advanced furnace with ceramic heat exchanger components. The indirect-fired system circumvents some of the technical challenges of a direct coal-fired system (Bannister et al., 1990). Proposed alternative designs have plant efficiencies that range up to 53 percent.
Experience With the TF40B Engine in the LCAC Fleet
Authors: House Edward M.
Published: March 2015

Four Textron Lycoming TF40B marine gas turbine engines are used to power the U.S. Navy’s Landing Craft Air Cushion (LCAC) vehicle. This is the first hovercraft of this configuration to be put in service for the Navy as a landing craft. The TF40B has experienced compressor blade pitting, carbon erosion of the first turbine blade and hot corrosion of the hot section. Many of these problems were reduced by changing the maintenance and operation of the LCAC. A Component Improvement Program (CIP) is currently investigating compressor and hot section coatings better suited for operation in a harsh marine environment. This program will also improve the performance of some engine components such as the bleed manifold and bearing seals.
Numerical and Experimental Analysis of the Flow in a Centrifugal Pump at Nominal and Partial Flow Rate
Authors: Combes J. F. , Rieutord E.
Published: March 2015

Detailed flow measurements in the impeller and the diffuser of an industrial centrifugal pump have been performed with a 2-component laser Doppler velocimeter. Measurements were made at 8 radial positions for flow rates ranging from 50% to 100% of design flow. The experimental results were compared to 3D turbulent flow calculations performed with a finite element code. At nominal flow rate, both measurements and calculations show a wake pattern along the suction side at the shroud. The flow is separated in the diffuser on the hub, and on the shroud at low flow rate. The inlet recirculation, occurring at 0.65 Qn is well predicted by the turbulent flow calculation.
Potential Flow Analysis of the Forces on a Laboratory Centrifugal Pump Impeller
Authors: Miner S. M. , Flack R. D. , Trevisan P.
Published: March 2015

Two dimensional potential flow was used to determine the pressure field in a laboratory centrifugal pump. The impeller and volute were modeled simultaneously, using the finite element technique. Simulation of impeller rotation was accomplished by generating steady state solutions with the impeller in 10 different angular orientations within the volute. As a result, the interaction between the impeller and volute developed naturally as a result of the solution. Model results showed that blade pressure profiles were asymmetric, even at design flow. These asymmetries were even more pronounced at off design flow rates. The causes of these asymmetries were examined in terms of the interaction between the impeller, and the tongue and discharge regions of the volute. In addition, the blade pressure profiles were integrated to determine the impeller unbalance force. The forces were calculated at design and off design flow rates. The frequency content of the forces was also examined. Fluctuating components of force, due to impeller orientation, were found to be on the order of 30% of the static force. Finally, a comparison was made between the computationally determined forces and measured forces reported in previous studies.
Reliability Analysis of Structural Ceramic Components Using a Three-Parameter Weibull Distribution
Authors: Duffy Stephen F. , Powers Lynn M. , Starlinger Alois
Published: March 2015

This paper describes nonlinear regression estimators for the three-parameter Weibull distribution. Issues relating to the bias and invariant associated with these estimators arc examined numerically using Monte Carlo simulation methods. The estimators were used to extract parameters from sintered silicon nitride failure data. A reliability analysis was performed on a turbopump blade utilizing the three-parameter Weibull distribution and the estimates from the sintered silicon nitride data.
Calculation of Wake-Induced Unsteady Flow in a Turbine Cascade
Authors: Cho N.-H. , Liu X. , Rodi W. , Schönung B.
Published: March 2015

Numerical predictions are reported of two-dimensional unsteady flow in a linear turbine cascade, where the unsteadiness is caused by passing wakes generated by the preceding row of blades. In particular, an experiment is simulated in which the passing wakes were generated by cylinders moving on a rotating squirrel cage. Blade-to-blade calculations were carried out by solving the unsteady 2D flow equations with an accurate finite-volume procedure, thereby resolving the periodic unsteady motion. The effects of stochastic turbulent fluctuations are simulated with a two-layer turbulence model, in which the standard k-ε model is applied in the bulk of the flow and a one-equation model in the near-wall region. This involves also a transition model based on an empirical formula due to Abu-Ghannam and Shaw (1980), which was adapted for the unsteady situation by applying it in a Lagrangean way, following fluid parcels in the boundary layer underneath disturbed and undisturbed free stream on their travel downstream. The calculations are compared with experiments for various wake-passing frequencies. On the whole, the complex unsteady flow behaviour is simulated realistically, including the moving forward of transition when the wake-passing frequency increases, but not all details can be reproduced.
Optimum Design of Rotor-Bearing Systems With Eigenvalue Constraints
Authors: Chen Ting-Yu , Wang Bo Ping
Published: March 2015

The analysis and design of rotor-bearing systems with gyroscopic effects are discussed in this paper. The original problem of this nonproportionally damped mechanism is transformed into the state space form so that the transformed problem is similar to the eigenvalue problem for an undamped system. It can be easily solved by widely available eigensolvers and the eigenvalue sensitivities needed for the design optimization can also be obtained conveniently using the transformed form. The sequential linear programming technique is employed to solve the design optimization problem. The easy implementation of this proposed approach with a general purpose finite element program is shown in the solution algorithm.
Infra-Red Signature Suppression for Marine Gas Turbines: Comparison of Sea Trial and Model Test Results for the DRES Ball IRSS System
Authors: Birk A. M. , Vandam D.
Published: March 2015

Sea Trials have recently been underway for Canada’s new City Class Patrol Frigate (CPF). These trials provided the first opportunity to measure the performance of the new DRES Ball Infra-red Signature Suppression (IRSS) system installed on a ship. Prior to these trials 1/4 scale hot flow model test and computer simulation performance results were available.

The CPF DRES Ball IRSS systems are installed on the exhaust uptakes of the GE LM2500 main gas turbines. The DRES Ball provides both metal surface cooling for all view angles and plume cooling. The DRES Ball significantly reduces the IR signature of the LM2500 exhaust.

This paper presents a comparison between the 1/4 scale hot flow model test results with the full scale sea trial results. Performance variables included in the comparison are; metal surface temperatures, back pressure, plume temperature distribution, and surface static pressures. Because of the confidential nature of the DRES Ball system performance, all classified data has been nondimensionalized so that only relative comparisons can be made between the full scale and 1/4 scale data.

The results show that the full scale system performs better than the 1/4 scale model because of Reynolds number effects. The plume temperature, surface temperatures and back pressure were all lower (better) than in the 1/4 scale model tests. One of the original concerns with the installation was that relative wind would degrade the performance of the DRES Ball onboard a ship. The wind effect was found to be benign during the trials.
Combustion System Performance and Field Test Results of the MS7001F Gas Turbine
Authors: Claeys James P. , Elward Kevin M. , Mick Warren J. , Symonds Richard A.
Published: March 2015

This paper presents the results of the combustion system test of the MS7001F installed at the Virginia Power Chesterfield station. Tests of water and steam injection for NOx control were performed. Results of emissions, combustor dynamics, and combustor hardware performance are presented. Emissions test results include NOx, CO, unburned hydrocarbons, VOC and formaldehyde levels. Combustor dynamic activity over a range of diluent injection ratios, and the performance of an actively cooled transition duct are also discussed. Combustion system mechanical performance is described following the first combustion system inspection.
Thermal Barrier Coatings on Turbine Blades by Plasma Spraying With Improved Cooling
Authors: Cosack T. , Pawlowski L. , Schneiderbanger S. , Sturlese S.
Published: March 2015

Turbine blades were coated with a thermal barrier coating system consisting of an MCrAlY bond coat about 100 μm thick deposited by Low Pressure Plasma Spraying (LPPS) and a 300 μm thick ZrO2-7wt.%Y2O3 top coat. The latter was manufactured by both Atmosphere and Temperature Controlled Spraying (ATCS) and Air Plasma Spraying (APS) using internal air cooling through the cooling holes of the turbine blades. Coated blades were submitted to thermal cycling tests in a burner rig with hot gas temperature of 1485°C. In the case of ATCS coated blades the number of cycles until the first spallation at the leading edge of the blade was between 350 and 2400. The number of cycles of the thermal barrier coatings sprayed with internal cooling was between 1200 and 1800. Furnace cycling tests were also carried out with ATCS coated blades at temperatures of 1100 and 1200°C. The results of thermal cycle tests and the investigations of the microstructure are discussed.
The Redesign of a Marine Gas Turbine Generator Set
Authors: Cheney P. , Abdelrazik A.
Published: March 2015

After suffering a poor record of reliability and performance deterioration, the gas turbine generator sets of the Canadian Navy Tribal Class destroyers were subjected to an extensive investigation and subsequent redesign. Major components were not found to be at fault but many deficiencies in the supporting equipment were found to be responsible for the high cost in labour and material for maintenance. Full scale model tests aided the redesign and early results of the first installation are very encouraging.

This paper describes many aspects of the redesign and provides some pointers for the successful design of a marine gas turbine installation.
The U.S. Navy’s Design, Development and Implementation Program for Gas Turbine Generator Sets
Authors: McGroarty John J.
Published: March 2015

The Design Development and Implementation Program (DDIP) evolved as a result of an organized progression of In-Service Engineering (ISE) responsibilities required to implement improvements to Gas Turbine Generator Sets (GTGS) in the U.S. Navy. The DDIP was established to bring a design concept, whether it be to correct a problem or to make a design improvement, from the drawing board through testing and development to the implementation of a Technical Directive as quickly as possible. Presently all engineering improvements on U.S. Navy Gas Turbine Generator Sets are implemented through the DDIP. Providing this central point of engineering has helped the Naval Sea Systems Command implement improvements in a well tested and timely manner.

This paper describes the sequential processes in the DDIP methodology and further discusses specific engineering problems and solutions using the DDIP process.
MS5002 Advanced Technology Uprate and Field Modification Experience
Authors: Ismoyo  , Kinney Carl D. , Grondahl Clayton M.
Published: March 2015

Advanced Technology turbine components have been developed for the GE MS5002 line of gas turbines that permit operation at a higher firing temperature. Those components include directionally solidified (DS) GTD-111 alloy stage-one buckets — the first GE application of a DS alloy in heavy-duty gas turbines. The Advanced Technology uprate improves turbine performance and extends turbine inspection intervals.

This paper provides an overview of the field modification of 21 mechanical drive units in Indonesia. The user’s technical objectives and uprate requirements are discussed along with installation experience and operating results to date. Advanced Technology component design features are illustrated and discussed in some detail with reference to their application in field units.
The VKI Compression Tube Annular Cascade Facility CT3
Authors: Sieverding C. H. , Arts T.
Published: March 2015

The purpose of this paper is to present the new transonic, annular facility developed at the von Karman Institute to investigate the aerodynamic heat transfer performances of real size advanced aero-engine and gas turbine components at correctly simulated operating conditions.

The facility operates under the principle of an Isentropic Light Piston Compression Tube. Its definite advantage over classical blowdown wind tunnels is to independently model the freestream Mach and Reynolds numbers as well as the gas/wall/coolant temperature ratios. Its running time ranges between 0.1 and 1 s.

The first part of the paper describes the design, the manufacturing and the installation of the different components of the wind tunnel and the test section. The second part deals with the different measurement techniques applied for aerodynamic and heat transfer measurements; it also describes some examples of the flow quality obtained in this new facility.
An Opto-Electronic Data Transmission System for Measurements on Rotating Turbomachinery Components
Authors: Sieverding C. H. , Vanhaeverbeek C. , Schulze G.
Published: March 2015

The paper presents the development of an opto-electronic data transmission system for high frequency measurements in rotating turbomachines. A model test rig was built to verify the response capabilities of the system for high speed rotating pressure probes traversing strong pressure gradient fields. Finally, the paper describes the construction of a rotating probe mechanism for measurements in a high speed annular turbine test rig.
Mechanical Properties, Oxidation Resistance and Their Interaction for Two Gas Turbine Seal Ring Alloys
Authors: Srivastava S. K.
Published: March 2015

HAYNES® 242™ alloy is a recently developed Ni-25Mo-8Cr alloy primarily for gas-turbine components requiring a combination of low-thermal expansion and high strength, such as seal rings. INCOLOY® alloy 909 is an iron-base Invar-type alloy used in similar applications. Alloy 909 exhibits substantial advantages over 242 alloy in RT and 650°C (1200°F) - 0.2% yield strength, although at considerable loss of ductility and toughness. In stress-rupture testing over a range of 540°-760°C (1000–1400°F), the 100-hr rupture strengths of alloy 909 are consistently inferior to those of the 242 alloy. This dichotomy in short-time versus long-time tensile properties is likely due to the poor oxidation resistance of alloy 909. Comparative static oxidation and oxidation data concurrent with stress-rupture testing for the two alloys are presented and discussed.
An Automotive Gas Turbine Engine Blade Erosion
Authors: Metwally M. , Tabakoff W. , Hamed A.
Published: March 2015

In this work, a study has been conducted to predict blade erosion and surface deterioration of the free power turbine of an automotive gas turbine engine. The blade material erosion model is based on three dimensional particle trajectory simulations in the three dimensional turbine flow field. The particle rebound characteristics after surface impacts were determined from experimental measurements of restitution ratios for blade material samples in a particulate flow tunnel. The trajectories provide the spacial distribution of the particle impact parameters over the blade surfaces. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions is used in the prediction of blade surface erosion based on the trajectory impact data. The results are presented for the three dimensional particle trajectories through the turbine blade passages, the particle impact locations, blade surface erosion pattern, and the associated erosion parameters. These parameters include impact velocity, impact angle and impact frequency. The data can be used for life prediction and performance deterioration of the automotive engine under investigation.
Trial Operations of Unit No. 1 Group 690 MW Combined Cycle Power Plant of Shin-Oita Power Station
Authors: Nogami S. , Ando N. , Noguchi Y. , Takahashi K. , Iwamiya T. , Hattori Y.
Published: March 2015

Kyushu Electric Power Co., Inc., in constructing the recently completed first phase of the No. 1 Group of Shin-Oita Power Plant, Oita Prefecture (Kyushu Island), achieved further improvements over previous combined cycle plants, especially in the area of plant overall operation. It is composed of six combined cycle power units of the single-shaft, non-reheat type, based on Hitachi-GE MS7001E gas turbines, with a total output of 690 MW.

Trial operations of the first unit began in May, 1990. Commercial operations of the first unit began in November 1990, and the last unit in June, 1991.

The NO.1 Group incorporates two major advances over previous combined cycle plants.

The first advance is a two-stage multiple nozzle dry-type low-NOx combustor. This combustor is a new development for keeping the level of NOx emissions below 62.5 ppm (16% O2 at gas turbine exhaust).

The second advance is a new functionally and hierarchically distributed digital control system. By the control system, the plant was designed to bring the following notable features:

1 The individual units can be started and stopped automatically from the load dispatching directive center at the head office.

2 The plant can be operated for high efficiency with short starting and stopping time and large load variations.

3 Plant operating characteristics for emergency operations can be improved remarkably, for instance, load run back operations and fast cut back operation, etc.

The results of trial operations have shown that the output per unit is about 0.5 to 4.2% higher, and the unit efficiency about 1.9 to 3.7% higher, than the planned values (all percentages relative), and tangible improvements and starting characteristics and load fluctuation are also satisfactory with the specified target values in the overall operation of the plant over that of previous combined cycle power plants.

This plant has satisfactorily been operated since the start of commercial operation.
A Study of Rotor Cavities and Heat Transfer in a Cooling Process in a Gas Tubine
Authors: Amano R. S. , Pavelic V.
Published: March 2015

A high temperature flow through a gas-turbine produces a high rate of turbulent heat transfer between the fluid flow field and the turbine components. The heat transfer process through rotor disks causes thermal stress due to the thermal gradient as well as the centrifugal force causes mechanical stresses; thus an accurate analysis for the evaluation of thermal behavior is needed. This paper presents a numerical study of thermal flow analysis in a two-stage turbine in order to better understand the detailed flow and heat transfer mechanisms through the cavity and the rotating rotor-disks. The numerical computations were performed to predict thermal fields throughout the rotating disks. The method used in this paper is the ‘segregation’ method which requires a much smaller number of grids than actually employed in the computations. The results are presented for temperature distributions through the disk and the velocity fields which illustrate the interaction between the cooling air flow and gas flow created by the disk rotation. The temperature distribution in the disks shows a reasonable trend. The numerical method developed in this study shows that it can be easily adapted for similar computations for air cooling flow patterns through any rotating blade disks in a gas turbine.
Performance of Gas Turbine Compressor Cleaners
Authors: Kolkman H. J.
Published: March 2015

Deposits are regularly removed from compressor blades and vanes of installed jet engines and gas turbines by compressor washing. Hereby a compressor cleaner is sprayed into the compressor while operating at reduced or normal r.p.m.

Recently developed compressor cleaners are claimed to be ecologically sound. In addition, many new compressor cleaners contain a corrosion inhibitor.

The cleaning efficiency of eight (old and new) compressor cleaners was determined by means of simulated compressor washing of compressor blades that had become foul in service. For the situation simulated, the cleaning efficiency of new, ecologically sound cleaners turned out to be poor as compared with old compressor cleaners.

The corrosion inhibition offered by those cleaners that contain a corrosion inhibitor was found to be satisfactory.
Combined Cycle Power Plant Start-Up Effects and Constraints of the HRSG
Authors: Pasha Akber
Published: March 2015

The heat recovery steam generator (HRSG) is an integral part of the combined cycle power plant which includes combustion turbine and steam turbine in addition to heat recovery steam generator. The start-up of the heat recovery steam generator, therefore, has an influence on the start-up of the total plant.

The paper discusses various constraints, both external and internal, which affect the Steam Generator start-up and in turn influence the start-up of the total plant. Considerations in the design of the steam generator to accommodate the plant start-up requirements, along with the effect of the cyclic or base loaded operation are also discussed.

The paper also presents a procedure which may be adopted in the conceptual design of the plant for an optimized system, a system which can accommodate the total plant start-up requirements without undue constraints on the availability of the full plant output.
Flow Studies in Ducted Twin-Rotor Contra-Rotating Axial Flow Fans
Authors: Roy Bhaskar , Ravibabu K. , Rao P. Srinivasa , Basu S. , Raju A. , Murthy P. N.
Published: March 2015

The design and testing of a 400 mm diameter contra-rotating fan unit was undertaken to study the flow behavior through the contra-rotating fans, and to find ways and means of improving their design and performance. The performance characteristics of the two-fan unit have shown that large overall stall margins can be achieved. Also, the effect of axial gaps showed that at the design speed combination best performance was observed at an axial gap of 50% of the 1st Fan chord.

Studies on the 2nd fan exit flow field, performance characteristics of individual fans and casing boundary layer development have been made. Significant performance enhancement is observed with serration on 2nd fan rotor blade surface. When casing boundary layer suction is employed in between the two blades, the 2nd fan exit flow shows better uniformity and increased total pressure at all radii. However, to obtain a large operating range, careful optimization of the 2nd rotor blade design would be required, taking into account peculiarities shown by the present study in variation of deviation and exit flow angles of the individual fans, and casing boundary layer development with increased axial pressure gradient.
Applications of Sound Intensity Measurements to Gas Turbine Engineering
Authors: Rawlinson R. D.
Published: March 2015

Recent advances in signal processing techniques have made the measurement of sound intensity a practical reality. The newly developed sound intensity meters can indicate both the magnitude and direction of sound. This is a major advantage over the traditional sound level meter which does not have such directional sensitivity. Sound intensity meters can, therefore, make accurate measurements under adverse conditions, such as onshore or offshore, where sound level meters may be unsuitable.

This makes the detailed assessment of the sound power output of a gas turbine package, operating in the field, practicable. Individual components of a gas turbine train can be evaluated so that the dominant noise sources can be identified, thereby providing more cost effective solutions to onshore and offshore installations.

This paper describes briefly the concepts of sound intensity, the current state of standards and some aspects of measurement technique. Case histories of the use of sound intensity instrumentation in a variety of situations, relevant to gas turbine engineering, will be described. This will include laboratory and field based investigations.
An Optimisation-Matching Procedure for Variable Cycle Jet Engines
Authors: Nascimento Marco A. R. , Pilidis Pericles
Published: March 2015

There are many advantages in employing Variable Cycle Engines for aircraft propulsion. These engines operate with two or more thermodynamic cycles, each suited to certain flight conditions.

One of the greatest challenges, during the design phase, is how to optimise the various cycles and then to match them to the capabilities of the components which make up the engine.

In this paper a general method is presented to carry out this exercise. The method is based on thermodynamic relationships and component characteristics. An example is included to illustrate the procedure.