Aerodynamic Performance and Turbulence Measurements in a Turbine Vane Cascade
Boyle, Robert J. (NASA Glenn Research Center, Cleveland, OH United States); Lucci, Barbara L. (NASA Glenn Research Center, Cleveland, OH United States); Senyitko, Richard G. (QSS Group, Inc., Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA/TM-2002-211709

Turbine vane aerodynamics were measured in a three vane linear cascade. Surface pressures and blade row losses were obtained over a range of Reynolds and Mach number for three levels of turbulence. Comparisons are made with predictions using a quasi-3D Navier-Stokes analysis. Turbulence intensity measurement were made upstream and downstream of the vane. The purpose of the downstream measurements was to determine how the turbulence was affected by the strong contraction through 75 deg turning.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-09

 

 

 

 

 

Effect of Favorable Pressure Gradients on Turbine Blade Pressure Surface Heat Transfer
Boyle, Robert J. (NASA Glenn Research Center, Cleveland, OH United States); Giel, P. W. (DYNACS Engineering Co., Inc., Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
2002

Recent measurements on a turbine rotor showed significant relaminarization effects. These effects were evident on the pressure surface heat transfer measurements. The character of the heat transfer varied with Reynolds number. Data were obtained for exit Reynolds numbers between 500,000 and 880,000. Tests were done with a high level of inlet turbulence, 7.5%. At lower Reynolds numbers the heat transfer was similar to that for laminar flow, but at a level higher than for laminar flow. At higher Reynolds numbers the heat transfer was similar to turbulent flow, when the acceleration parameter, K, was sufficiently small. The proposed paper discusses the experimental results, and also discusses approaches to calculating the surface heat transfer for the blade surface. Calculations were done using a three-dimensional Navier-Stokes CFD analysis. The results of these tests, when compared with previous blade tests in the same facility, illustrate modeling difficulties that were encountered in CFD predictions. The two blades were in many ways similar. However, the degree of agreement between the same analysis and the experimental data was significantly different. These differences are highlighted to illustrate where improvements in modeling approaches are needed for transitional flows.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Prediction of Relaminarization Effects on Turbine Blade Heat Transfer
Boyle, R. J. (NASA Glenn Research Center, Cleveland, OH United States); Giel, P. W. (QSS Group, Inc., Brook Park, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA/TM-2001-210978

An approach to predicting turbine blade heat transfer when turbulent flow relaminarizes due to strong favorable pressure gradients is described. Relaminarization is more likely to occur on the pressure side of a rotor blade. While stators also have strong favorable pressure gradients, the pressure surface is less likely to become turbulent at low to moderate Reynolds numbers. Accounting for the effects of relaminarization for blade heat transfer can substantially reduce the predicted rotor surface heat transfer. This in turn can lead to reduced rotor cooling requirements. Two-dimensional midspan Navier-Stokes analyses were done for each of eighteen test cases using eleven different turbulence models. Results showed that including relaminarization effects generally improved the agreement with experimental data. The results of this work indicate that relatively small changes in rotor shape can be utilized to extend the likelihood of relaminarization to high Reynolds numbers. Predictions showing how rotor blade heat transfer at a high Reynolds number can be reduced through relaminarization are given.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Comparison of Predicted and Measured Turbine Vane Rough Surface Heat Transfer
Boyle, R. J. (NASA Glenn Research Center, Cleveland, OH United States); Spuckler, C. M. (NASA Glenn Research Center, Cleveland, OH United States); Lucci, B. L. (NASA Glenn Research Center, Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA/TM-2000-210219

The proposed paper compares predicted turbine vane heat transfer for a rough surface over a wide range of test conditions with experimental data. Predictions were made for the entire vane surface. However, measurements were made only over the suction surface of the vane, and the leading edge region of the pressure surface. Comparisons are shown for a wide range of test conditions. Inlet pressures varied between 3 and 15 psia, and exit Mach numbers ranged between 0.3 and 0.9. Thus, while a single roughened vane was used for the tests, the effective rougness,(k(sup +)), varied by more than a factor of ten. Results were obtained for freestream turbulence levels of 1 and 10%. Heat transfer predictions were obtained using the Navier-Stokes computer code RVCQ3D. Two turbulence models, suitable for rough surface analysis, are incorporated in this code. The Cebeci-Chang roughness model is part of the algebraic turbulence model. The k-omega turbulence model accounts for the effect of roughness in the application of the boundary condition. Roughness causes turbulent flow over the vane surface. Even after accounting for transition, surface roughness significantly increased heat transfer compared to a smooth surface. The k-omega results agreed better with the data than the Cebeci-Chang model. However, the low Reynolds number k-omega model did not accurately account for roughness when the freestream turbulence level was low. The high Reynolds number version of this model was more suitable when the freestream turbulence was low.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Infrared Low-Temperature Turbine Vane Rough Surface Heat Transfer Measurements
Boyle, R. J. (NASA Glenn Research Center, Cleveland, OH United States); Spuckler, C. M. (NASA Glenn Research Center, Cleveland, OH United States); Lucci, B. L. (NASA Glenn Research Center, Cleveland, OH United States); Camperchioli, W. P. (NASA Glenn Research Center, Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
Paper-2000-GT-216 , 2001

Turbine vane heat transfer distributions obtained using an infrared camera technique are described. Infrared thermography was used because noncontact surface temperature measurements were desired. Surface temperatures were 80 C or less. Tests were conducted in a three-vane linear cascade, with inlet pressures between 0.14 and 1.02 atm, and exit Mach numbers of 0.3, 0.7, and 0.9, for turbulence intensities of approximately 1 and 10 percent. Measurements were taken on the vane suction side, and on the pressure side leading edge region. The designs for both the vane and test facility are discussed. The approach used to account for conduction within the vane is described. Midspan heat transfer distributions are given for the range of test conditions.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Mach Number Effects on Turbine Blade Transition Length Prediction
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH United States); Simon, F. F. (NASA Lewis Research Center, Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA/TM-1998-208404

The effect of a Mach number correction on a model for predicting the length of transition was investigated. The transition length decreases as the turbulent spot production rate increases. Much of the data for predicting the spot production rate comes from low speed flow experiments. Recent data and analysis showed that the spot production rate is affected by Mach number. The degree of agreement between analysis and data for turbine blade heat transfer without film cooling is strongly dependent of accurately predicting the length of transition. Consequently, turbine blade heat transfer data sets were used to validate a transition length turbulence model. A method for modifying models for the length of transition to account for Mach number effects is presented. The modification was made to two transition length models. The modified models were incorporated into the two-dimensional Navier-Stokes code, RVCQ3D. Comparisons were made between predicted and measured midspan surface heat transfer for stator and rotor turbine blades. The results showed that accounting for Mach number effects significantly improved the agreement with the experimental data.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Aerodynamics of a Transitioning Turbine Stator Over a Range of Reynolds Numbers
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH United States); Lucci, B. L. (NASA Lewis Research Center, Cleveland, OH United States); Verhoff, V. G. (NASA Lewis Research Center, Cleveland, OH United States); Camperchioli, W. P. (NASA Lewis Research Center, Cleveland, OH United States); La, H. (NASA Lewis Research Center, Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA/TM-1998-208408

Midspan aerodynamic measurements for a three vane-four passage linear turbine vane cascade are given. The vane axial chord was 4.45 cm. Surface pressures and loss coefficients were measured at exit Mach numbers of 0.3, 0.7, and 0.9. Reynolds number was varied by a factor of six at the two highest Mach numbers, and by a factor of ten at the lowest Mach number. Measurements were made with and without a turbulence grid. Inlet turbulence intensities were less than I% and greater than IO%. Length scales were also measured. Pressurized air fed the test section, and exited to a low pressure exhaust system. Maximum inlet pressure was two atmospheres. The minimum inlet pressure for an exit Mach number of 0.9 was one-third of an atmosphere, and at a Mach number of 0.3, the minimum pressure was half this value. The purpose of the test was to provide data for verification of turbine vane aerodynamic analyses, especially at low Reynolds numbers. Predictions obtained using a Navier-Stokes analysis with an algebraic turbulence model are also given.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Prediction of Nonuniform Inlet Temperature Effects on Vane and Rotor Heat Transfer
Boyle, Robert J. (NASA Lewis Research Center, Cleveland, OH United States); Giel, Paul W. (NYMA, Inc., Brook Park, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-107539 , 1997

The effects of nonuniform combustor exit temperature profiles on vane and rotor heat transfer were determined using a steady-state three-dimensional Navier-Stokes analysis. Both radial and tangential nonuniform temperature profiles were individually considered. Comparisons are made with experimental data for the effects of a radial temperature nonuniformity on rotor heat transfer. There was a decrease in stator heat load, and an increase in rotor heat load for a radial temperature distribution typically seen at the combustor exit. Tangential variations in stator inlet temperature produced significant variations in stator heat load, and resulted in average rotor heat load greater than for the uniform inlet temperature case. Rotor heat load was also calculated for different stator wake locations. Accounting for the stator wake position at the rotor inlet gave a greater average rotor heat load than that obtained by averaging the stator exit flow field in the tangential direction. The increase was most notable on the rotor pressure surface.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Predicted Turbine Heat Transfer for a Range of Test Conditions
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH United States); Lucci, B. L. (NASA Lewis Research Center, Cleveland, OH United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-107374 , 1996

Comparisons are shown between predictions and experimental data for blade and endwall heat transfer. The comparisons of computational domain parisons are given for both vane and rotor geometries over an extensive range of Reynolds and Mach numbers. Comparisons are made with experimental data from a variety of sources. A number of turbulence models are available for predicting blade surface heat transfer, as well as aerodynamic performance. The results of an investigation to determine the turbulence model which gives the best agreement with experimental data over a wide range of test conditions are presented.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Heat transfer predictions for two turbine nozzle geometries at high Reynolds and Mach numbers
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH, United States); Jackson, R. (Defence Research Agency, Farnborough, Hampshire, United Kingdom)
NASA Center for AeroSpace Information (CASI)
NASA-TM-106956 , 1995

Predictions of turbine vane and endwall heat transfer and pressure distributions are compared with experimental measurements for two vane geometries. The differences in geometries were due to differences in the hub profile, and both geometries were derived from the design of a high rim speed turbine (HRST). The experiments were conducted in the Isentropic Light Piston Facility (ILPF) at Pyestock at a Reynolds number of 5.3 x 10(exp 6), a Mach number of 1.2, and a wall-to-gas temperature ratio of 0.66. Predictions are given for two different steady-state three-dimensional Navier-Stokes computational analyses. C-type meshes were used, and algebraic models were employed to calculate the turbulent eddy viscosity. The effects of different turbulence modeling assumptions on the predicted results are examined. Comparisons are also given between predicted and measured total pressure distributions behind the vane. The combination of realistic engine geometries and flow conditions proved to be quite demanding in terms of the convergence of the CFD solutions. An appropriate method of grid generation, which resulted in consistently converged CFD solutions, was identified.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Grid orthogonality effects on predicted turbine midspan heat transfer and performance
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH, United States); Ameri, A. A. (Kansas Univ., Lawrence, KS., United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-106931 , 1995

The effect of five different C type grid geometries on the predicted heat transfer and aerodynamic performance of a turbine stator is examined. Predictions were obtained using two flow analysis codes. One was a finite difference analysis, and the other was a finite volume analysis. Differences among the grids in terms of heat transfer and overall performance were small. The most significant difference among the five grids occurred in the prediction of pitchwise variation in total pressure. There was consistency between results obtained with each of the flow analysis codes when the same grid was used. A grid generating procedure in which the viscous grid is embedded within an inviscid type grid resulted in the best overall performance.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Prediction of incidence and surface roughness effects on turbine performance
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH, United States)
NASA Center for AeroSpace Information (CASI)
1993

The results of a Navier-Stokes analysis for predicting the change in turbine efficiency due to a change in either incidence or surface roughness is discussed. It was experimentally determined by Boynton, Tabibzadeh, and Hudson that polishing the SSME high pressure fuel turbine blades improved turbine efficiency by about 2 points over a wide range of operating conditions. These conditions encompassed the range of incidence seen by the turbine blading during flight. It is also necessary to be able to predict turbine performance at various operating points for future rocket turbopump applications. The code RVCQ3D, developed by Rod Chima, was used to determine the effects of changes in incidence angle on turbine blade row efficiency. The midspan Navier-Stokes results were used in conjunction with an inviscid flow analysis code to predict the efficiency of the two stage SSME over a wide range of operating conditions for smooth and rough turbine blades. The use of the Navier-Stokes analysis to predict changes in turbine efficiency due to variation in incidence angles was found to be superior to other incidence loss correlations available in the literature. The sensitivity of the Navier-Stokes results to grid parameters is discussed. The effects of the surface roughness were accounted for using the Cebeci-Chang rough wall turbulence model. This model was implemented in the code RVCQ3D. The implementation of this model for predicting the change in efficiency is also discussed.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

 

Three-dimensional Navier-Stokes heat transfer predictions for turbine blade rows
Boyle, Robert J. (NASA Lewis Research Center, Cleveland, OH, United States); Giel, Paul W. (Sverdrup Technology, Inc., Brook Park, OH., United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-105800 , 1992

Results are shown for a three-dimensional Navier-Stokes analysis of both the flow and the surface heat transfer for turbine applications. Heat transfer comparisons are made with the experimental shock-tunnel data of Dunn and Kim, and with the data of Blair for the rotor of the large scale rotating turbine. The analysis was done using the steady-state, three-dimensional, thin-layer Navier-Stokes code developed by Chima, which uses a multistage Runge-Kutta scheme with implicit residual smoothing. An algebraic mixing length turbulence model is used to calculate turbulent eddy viscosity. The variation in heat transfer due to variations in grid parameters is examined. The effects of rotation, tip clearance, and inlet boundary layer thickness variation on the predicted blade and endwall heat transfer are examined.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Two-dimensional Navier-Stokes heat transfer analysis for rough turbine blades
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH, United States); Civinskas, K. C. (NASA Lewis Research Center, Cleveland, OH, United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-106008 , 1991

A quasi-three-dimensional thin-layer Navier-Stokes analysis was used to predict heat transfer to rough surfaces. Comparisons are made between predicted and experimental heat transfer for turbine blades and flat plates of known roughness. The effect of surface roughness on heat transfer was modeled using a mixing length approach. The effect of near-wall grid spacing and convergence criteria on the accuracy of the heat transfer predictions are examined. An eddy viscosity mixing length model having an inner and outer layer was used. A discussion of the appropriate model for the crossover between the inner and outer layers is included. The analytic results are compared with experimental data for both flat plates and turbine blade geometries. Comparisons between predicted and experimental heat transfer showed that a modeling roughness effects using a modified mixing length approach results in good predictions of the trends in heat transfer due to roughness.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Navier-Stokes analysis of turbine blade heat transfer
Boyle, R. J. (NASA Lewis Research Center, Cleveland, OH, United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-102496 , 1990

Comparisons with experimental heat transfer and surface pressures were made for seven turbine vane and blade geometries using a quasi-three-dimensional thin-layer Navier-Stokes analysis. Comparisons are made for cases with both separated and unseparated flow over a range of Reynolds numbers and freestream turbulence intensities. The analysis used a modified Baldwin-Lomax turbulent eddy viscosity mode. Modifications were made to account for the effects of: (1) freestream turbulence on both transition and leading edge heat transfer; (2) strong favorable pressure gradients on relaminarization; and (3) variable turbulent Prandtl number heat transfer. In addition, the effect of heat transfer on the near wall model of Deissler is compared with the Van Driest model.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08

 

 

 

 

 

Experimental determination of stator endwall heat transfer
Boyle, Robert J. (NASA Lewis Research Center, Cleveland, OH, United States); Russell, Louis M. (NASA Lewis Research Center, Cleveland, OH, United States)
NASA Center for AeroSpace Information (CASI)
NASA-TM-101419 , 1989

Local Stanton numbers were experimentally determined for the endwall surface of a turbine vane passage. A six vane linear cascade having vanes with an axial chord of 13.81 cm was used. Results were obtained for Reynolds numbers based on inlet velocity and axial chord between 73,000 and 495,000. The test section was connected to a low pressure exhaust system. Ambient air was drawn into the test section, inlet velocity was controlled up to a maximum of 59.4 m/sec. The effect of the inlet boundary layer thickness on the endwall heat transfer was determined for a range of test section flow rates. The liquid crystal measurement technique was used to measure heat transfer. Endwall heat transfer was determined by applying electrical power to a foil heater attached to the cascade endwall. The temperature at which the liquid crystal exhibited a specific color was known from a calibration test. Lines showing this specific color were isotherms, and because of uniform heat generation they were also lines of nearly constant heat transfer. Endwall static pressures were measured, along with surveys of total pressure and flow angles at the inlet and exit of the cascade.
No Digital Version Available - Order This Document
Updated/Added to NTRS: 2003-05-08