Pressure measurements in a scramjet combustor with film cooling

2000 ◽  
Author(s):  
S. Rowan ◽  
A. Paull
Keyword(s):  
Film Cooling ◽  
Pressure Measurements ◽  
Scramjet Combustor

Validation of Surface Pressure Predictions for Nozzle Airfoil and Endwall Film Cooling Design Using Transonic Cascade Measurements

2013 ◽  
Author(s):  
Jason E. Dees ◽  
James A. Tallman ◽  
Michael A. Heminger ◽  
Daniel Wilde
Keyword(s):  
Surface Pressure ◽  
Film Cooling ◽  
Static Pressure ◽  
Experimental Studies ◽  
Tangential Direction ◽  
Maximum Deviation ◽  
Pressure Measurements ◽  
Local Flow ◽  
Cooling Design ◽  
Transonic Cascade

This study compares surface pressure measurements and predictions for a high pressure turbine first-stage nozzle vane. The surface pressure measurements were taken in a 3D annular cascade, consisting of four airfoils and five passages. The cascade was uncooled, axisymmetric at both inner and outer endwalls, and reproduced the design intent Reynolds and Mach numbers of the real engine component. Static pressure measurements were taken along the airfoil profile at 15, 50, and 85% span, with duplicate midspan measurements across the four airfoils for assessing the tangential periodicity of the flow. Static pressure measurements were also taken on the inner and outer endwall surfaces of the center airfoil passage, with 40 measurement points uniformly distributed over each endwall. Three methods of surface pressure prediction were compared with the data: (1) a 2D inviscid CFD solution of a single airfoil passage at fixed spanwise locations, (2) a 3D RANS CFD solution of a single airfoil passage, and (3) a 3D RANS CFD solution of the full five-passage cascade domain. Both of the single-passage solutions assumed flowfield periodicity in the tangential direction and compared favorably to the center passage airfoil data. This finding suggested that the cascade center passage was sufficiently representative of the full-annulus turbomachine environment and validated the cascade for further experimental studies. The adjacent airfoil pressure measurements quantified the passage-to-passage variation in the cascade flowfield, and the 3D full-cascade CFD compared favorably with the peripheral airfoil data. The full-cascade CFD also compared favorably with the data on both endwalls: with an average and maximum deviation of 0.5 and 2%, respectively. These findings provide confidence in the 3D CFD methods for use in determining local flow rates from cooling/leakage geometry, and serve as an important first step toward validating the methods for real-engine blockage effects like coolant and endwall contouring.

Comparative Study Between a Cut-Back and Conventional Trailing Edge Film Cooling System

2006 ◽  
Author(s):  
Janendra C. Telisinghe ◽  
Peter T. Ireland ◽  
Terry V. Jones ◽  
David Barrett ◽  
Changmin Son
Keyword(s):  
Turbine Blade ◽  
Film Cooling ◽  
Total Pressure ◽  
Cooling System ◽  
Pressure Measurements ◽  
Flat Plates ◽  
Trailing Edge ◽  
Scaled Model ◽  
Cooling Hole ◽  
Low Speed Wind Tunnel

The present experimental study investigates the aero performance differences between a conventional turbine blade trailing edge and a trailing edge with a sharp cut-back. Both geometries include trailing edge film cooling. A scaled model of a conventional turbine blade trailing edge and the trailing edge with a sharp cut-back including the scaled film cooling hole geometries were incorporated into flat plates. Experiments were conducted in a low speed wind tunnel to establish the performance change caused by introducing such a cut-back system on the trailing edge. Experiments were conducted at a Reynolds number of 1.9 × 106 at the trailing edge and for blowing ratios from 0.9 to 2.4. The experimental data presented include; static pressure variation on the plate surfaces; the change in discharge coefficient due to the cut-back; detailed total pressure measurements via a 2D traverse mechanism at a plane 40mm downstream of the flat plates. The total pressure measurements were used to establish the mixed out loss for both configurations.

Aerodynamic and Heat Flux Measurements in a Single-Stage Fully Cooled Turbine—Part II: Experimental Results

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
C. W. Haldeman ◽  
R. M. Mathison ◽  
M. G. Dunn ◽  
S. A. Southworth ◽  
J. W. Harral ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Pressure ◽  
Film Cooling ◽  
Single Stage ◽  
Pressure Measurements ◽  
Surface Geometry ◽  
Adiabatic Wall ◽  
Pressure Surface ◽  
Flux Measurements ◽  
Total Temperature

This paper presents measurements and the companion computational fluid dynamics (CFD) predictions for a fully cooled, high-work single-stage HP turbine operating in a short-duration blowdown rig. Part I of this paper (Haldeman, C. W., Mathison, R. M., Dunn, M. G., Southworth, S. A., Harral, J. W., and Heltland, G., 2008, ASME J. Turbomach., 130(2), p. 021015) presented the experimental approach, and Part II focuses on the results of the measurements and demonstrates how these results compare to predictions made using the Numeca FINE/Turbo CFD package. The measurements are presented in both time-averaged and time-accurate formats. The results include the heat transfer at multiple spans on the vane, blade, and rotor shroud as well as flow path measurements of total temperature and total pressure. Surface pressure measurements are available on the vane at midspan, and on the blade at 50% and 90% spans as well as the rotor shroud. In addition, temperature and pressure measurements obtained inside the coolant cavities of both the vanes and blades are presented. Time-averaged values for the surface pressure on the vane and blade are compared to steady CFD predictions. Additional comparisons will be made between the heat transfer on cooled blades and uncooled blades with identical surface geometry. This, along with measurements of adiabatic wall temperature, will provide a basis for analyzing the effectiveness of the film cooling scheme at a number of locations.

Aerodynamic and Heat Flux Measurements in a Single Stage Fully Cooled Turbine: Part II — Experimental Results

2006 ◽  
Author(s):  
C. W. Haldeman ◽  
R. M. Mathison ◽  
M. G. Dunn ◽  
S. Southworth ◽  
J. W. Harral ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Pressure ◽  
Film Cooling ◽  
Single Stage ◽  
Pressure Measurements ◽  
Surface Geometry ◽  
Adiabatic Wall ◽  
Pressure Surface ◽  
Flux Measurements ◽  
Total Temperature

This paper presents measurements and the companion CFD predictions for a fully cooled, high-work single stage HP turbine operating in a short-duration blowdown rig. Part I of this paper presented the experimental approach, and Part II focuses on the results of the measurements and demonstrates how these results compare to predictions made using the Numeca FINE/Turbo CFD package. The measurements are presented in both time-averaged and time-accurate formats. The results include the heat transfer at multiple spans on the vane, blade, and rotor shroud as well as flow path measurements of total temperature and total pressure. Surface pressure measurements are available on the vane at midspan, and on the blade at 50% and 90% spans as well as the rotor shroud. In addition, temperature and pressure measurements obtained inside the coolant cavities of both the vanes and blades are presented. Time-averaged values for the surface pressure on the vane and blade are compared to steady CFD predictions. Additional comparisons will be made between the heat transfer on cooled blades and uncooled blades with identical surface geometry. This, along with measurements of adiabatic wall temperature, will provide a basis for analyzing the effectiveness of the film-cooling scheme at a number of locations.

Optical and Pressure Measurements in Shock Tunnel Testing of a Model Scramjet Combustor

1997 ◽  
Vol 13 (3) ◽  
pp. 388-394 ◽  
Author(s):  
T. J. McIntyre ◽  
A. F. P. Houwing ◽  
P. C. Palma ◽  
P. A. B. Rabbath ◽  
J. S. Fox
Keyword(s):  
Shock Tunnel ◽  
Pressure Measurements ◽  
Scramjet Combustor ◽  
Tunnel Testing

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

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