Time-Averaged Heat-Flux Distributions and Comparison With Prediction for the Teledyne 702 HP Turbine Stage

1988 ◽  
Vol 110 (1) ◽  
pp. 51-56 ◽  
Author(s):  
M. G. Dunn ◽  
R. E. Chupp
Keyword(s):  
Thin Film ◽  
Heat Flux ◽  
Shock Tube ◽  
Flat Plate ◽  
Leading Edge ◽  
Turbine Stage ◽  
Heated Air ◽  
Edge Distribution ◽  
Flux Measurements ◽  
Good Agreement

Time-averaged heat-flux distributions are reported for the vane and blade of the Teledyne CAE 702 HP full-stage rotating turbine. A shock tube is used as a short-duration source of heated air to which the turbine is subjected and thin-film gages are used to obtain the heat-flux measurements. The thin-film gages were concentrated on the midspan region from the leading edge to near the trailing edge. The blade contained two contoured inserts wtih gages spaced very close together so that the leading edge distribution could be resolved. The NGV and blade results are compared with predictions obtained using a flat-plate technique, an eddy-diffusing model (STAN 5), and a k–ε model. The results of the comparison between data and prediction suggest that: (a) first, the vane data are bounded by the turbulent flat plate and the fully turbulent STAN 5 prediction. For the vane, the k–ε prediction is in relatively good agreement with the STAN 5 prediction and (b) secondly, the blade data are acceptably predicted by the k–ε prediction on both the pressure and the suction surfaces. The STAN 5 fully turbulent calculation for the blade falls above the data (essentially in agreement with the turbulent flat-plate calculation) and the STAN 5 fully laminar falls substantially below the data. With the exception of the pressure loadings and the geometry, the code inputs used for these predictions were identical to those previously used to predict the Garrett TFE 731-2 HP turbine and the Garrett LART HP turbine.

Heat-Flux Measurements for the Rotor of a Full-Stage Turbine: Part I—Time-Averaged Results

1986 ◽  
Vol 108 (1) ◽  
pp. 90-97 ◽  
Author(s):  
M. G. Dunn
Keyword(s):  
Heat Flux ◽  
Flat Plate ◽  
Guide Vane ◽  
Flow Direction ◽  
Leading Edge ◽  
Present Calculation ◽  
Suction Surface ◽  
Pressure Surface ◽  
Good Comparison ◽  
Flux Measurements

This paper describes time-averaged heat-flux distributions obtained for the blade of a Garrett TFE 731-2 hp full-stage rotating turbine. Blade measurements were obtained both with and without injection. The injected gas was supplied from a separate reservoir and was directed into the turbine gas path via nozzle guide vane (NGV) pressure surface slots located at approximately 63 percent of the wetted distance. Blade heat-flux measurements were performed for two different injection gas temperatures, Tc/T0 = 0.53 and Tc/T0 = 0.82. A shock tube is used as a short-duration source of heated air to which the turbine is subjected and thin-film gages are used to obtain the heat-flux measurements. Results are presented along the blade in the flow direction at 10, 50, and 90 percent span for both the pressure and suction surfaces. A sufficient number of measurements were obtained to also present span-wise distributions. At approximately the 50 percent span location, two contoured inserts containing closely spaced gages were installed in the blade so that the leading-edge region distribution could be resolved in detail. The blade results are compared with predictions obtained using a flat-plate technique and with predictions obtained using a version of STAN 5. The results suggest that: (1) The suction surface laminar flat-plate prediction is in reasonable agreement with the data from the stagnation point up to approximately 10 percent of the wetted distance. Beyond 10 percent, the laminar prediction falls far below the data and the turbulent flat-plate prediction falls above the data by about 60 percent. The laminar portion of the STAN 5 prediction as configured for the present calculation does not provide good comparison with the data. However, the turbulent flat-plate boundary-layer portion of STAN 5 does provide reasonably good comparison with the data. On the pressure surface, the turbulent flat-plate prediction is in good agreement with the data, but the laminar flat-plate and the STAN 5 predictions fall far low. (2) The influence of upstream NGV injection is to significantly increase the local blade heat flux in the immediate vicinity of the leading edge; i.e., up to 20 percent wetted distance on the suction surface and up to 10 percent on the pressure surface. (3) The effect on local heat flux of increasing the coolant-gas temperature was generally less than 10 percent.

Turbine Heat Flux Measurements: Influence of Slot Injection on Vane Trailing Edge Heat Transfer and Influence of Rotor on Vane Heat Transfer

1985 ◽  
Vol 107 (1) ◽  
pp. 76-83 ◽  
Author(s):  
M. G. Dunn
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Leading Edge ◽  
Temperature Ratio ◽  
Trailing Edge ◽  
Heated Air ◽  
Flux Measurements ◽  
Nozzle Guide ◽  
Nozzle Guide Vanes ◽  
Blowing Parameter

This paper describes the measurement of heat flux distributions obtained for a Garrett TFE 731-2 hp turbine. Measurements were obtained for a full turbine both with and without injection and for the nozzle guide vanes with and without a rotor. A shock tube is used as a short-duration source of heated air and miniature thin-film gages are used to obtain the heat flux measurements. Results are presented for values of the blowing parameter (ρcVc/ρ∞V∞)at SLOT, in the range of 0.8–1.3. The injection gas (air) as a percentage of turbine weight flow, Wc/Wo, was in the range of 2.1–3.5 percent. A comparison is presented between results obtained with the rotor operating at 100 percent of corrected speed and those obtained with the rotor replaced by a row of flow straighteners. The results suggest that: (i) the reduction of heat flux due to injection is a function of the blowing parameter, the temperature ratio, and the physical location relative to the tip or hub endwall and (ii) the presence of the rotor has a significant affect on the vane trailing edge Stanton number, increasing it by 15 to 25 percent. The vane leading edge and midchord regions were generally unaffected.

Measurement of Heat Flux and Pressure in a Turbine Stage

1981 ◽  
Author(s):  
M. G. Dunn ◽  
A. Hause
Keyword(s):  
Heat Flux ◽  
Reynolds Numbers ◽  
Wall Region ◽  
Pressure Measurements ◽  
Turbine Stage ◽  
Flux Measurements ◽  
Film Heat Transfer ◽  
End Wall ◽  
High Temperature High Pressure ◽  
Good Agreement

Selected portions of the first-stage stationary inlet nozzle, shroud, and rotor of the AiResearch TFE 731-2 turbine were instrumented with thin-film heat-transfer gages and heat-flux measurements were performed using a shock tunnel as a source of high-temperature, high-pressure gas. Experiments were performed over a range of Reynolds numbers, based on mid-annular stator chord, from 1.6 × 105 to 3.1 × 105 and corrected speeds from approximately 70 to 106 percent. The full-stage heat-flux results are compared to our previous measurements obtained with a stator only, in the absence of a rotor. The previous results are in good agreement with the full-stage data for the tip end-wall region, but they are significantly less than the full-stage results for the stator airfoil. Pressure measurements were obtained throughout the model and these results are shown to be in excellent agreement with the steady-state rig data supplied to us by AiResearch for this turbine. Heat-flux measurements are also presented for the stationary shroud as a function of rotor mid-annular chord. The shroud heat flux data are shown to be in excess of the rotor blade results. Rotor-tip heat flux measurements are likewise shown to be slightly greater than the shroud results.

Measurement of Heat Flux and Pressure in a Turbine Stage

1982 ◽  
Vol 104 (1) ◽  
pp. 215-223 ◽  
Author(s):  
M. G. Dunn ◽  
A. Hause
Keyword(s):  
Heat Flux ◽  
Reynolds Numbers ◽  
Wall Region ◽  
Pressure Measurements ◽  
Turbine Stage ◽  
Flux Measurements ◽  
Film Heat Transfer ◽  
End Wall ◽  
High Temperature High Pressure ◽  
Good Agreement

Selected portions of the first stage stationary inlet nozzle, shroud, and rotor of the AiResearch TFE 731-2 turbine were instrumented with thin-film heat-transfer gages and heat-flux measurements were performed using a shock tunnel as a source of high-temperature, high-pressure gas. Experiments were performed over a range of Reynolds numbers, based on mid-annular stator chord, from 1.6 × 105 to 3.1 × 105 and corrected speeds from approximately 70–106 percent. The full-stage heat-flux results are compared to our previous measurements obtained with a stator only, in the absence of a rotor. The previous results are in good agreement with the full-stage data for the tip end-wall region, but they are significantly less than the full-stage results for the stator airfoil. Pressure measurements were obtained throughout the model and these results are shown to be in excellent agreement with the steady-state rig data supplied to us by AiResearch for this turbine. Heat-flux measurements are also presented for the stationary shroud as a function of rotor mid-annular chord. The shroud heat-flux data are shown to be in excess of the rotor blade results. Rotor-tip heat-flux measurements are shown to be slightly greater than the shroud results.

Aeroelastic Stability Analysis of Supersonic Cascades

1979 ◽  
Vol 101 (4) ◽  
pp. 533-541 ◽  
Author(s):  
J. A. Strada ◽  
W. R. Chadwick ◽  
M. F. Platzer
Keyword(s):  
Flat Plate ◽  
Leading Edge ◽  
Experimental Information ◽  
Nonlinear Method ◽  
Three Solutions ◽  
Blade Loading ◽  
Pressure Distributions ◽  
Blade Thickness ◽  
Analytical Expressions ◽  
Good Agreement

This paper presents three solutions for the analysis of supersonic flow past oscillating cascades with subsonic leading-edge locus. A quite elementary solution is first developed for the case of slowly oscillating finite and infinite flat plate cascades which provides simple analytical expressions for the unsteady pressure distributions. Comparisons with other solutions show generally excellent agreement. Furthermore, a previously developed linearized characteristics solution for finite flat plate cascades is applied to the case of superresonant blade motions. Again, the unsteady blade loading distributions are found to be in good agreement with Verdon’s recent infinite cascade solution for this case. Finally, a nonlinear method of characteristics solution for finite cascades is described which permits the analysis of blade thickness effects on flutter. At this time, only the inlet and passage flow computations have been completed which are compared with the available experimental information.

Wind-Related Heat Transfer Coefficient for Flat-Plate Solar Collectors

1987 ◽  
Vol 109 (2) ◽  
pp. 108-110 ◽  
Author(s):  
S. Shakerin
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flat Plate ◽  
Separation Bubble ◽  
Convective Heat Transfer Coefficient ◽  
Leading Edge ◽  
The Heat Transfer Coefficient ◽  
Good Agreement

Experiments were performed to evaluate the convective heat transfer coefficient for a flat plate mounted in a wooden model of a roof of a building. The experiments were carried out in a closed-circuit wind tunnel and included parametric adjustments of the roof tilt and Reynolds number, based on the length of the plate. The roof tilt was set at 0, 30, 45, 60, and 90 degrees and the Reynolds number ranged from 58,000 to 250,000. A transient, one lump, thermal approach was used for heat transfer calculations. Due to a separation bubble at the leading edge of the model, i.e., the roof, at angles of attack of less than 40 degrees, the flow became turbulent after reattachment. This resulted in a higher heat transfer than previously reported in the literature. At higher angles of attack, the flow was not separated at the leading edge and remained laminar. The heat transfer coefficient for higher angles of attack, i.e., α > 40 deg, was found to be approximately independent of the angle of attack and in good agreement with the previously published results.

Heat-Flux Measurements for the Rotor of a Full-Stage Turbine: Part II—Description of Analysis Technique and Typical Time-Resolved Measurements

1986 ◽  
Vol 108 (1) ◽  
pp. 98-107 ◽  
Author(s):  
M. G. Dunn ◽  
W. K. George ◽  
W. J. Rae ◽  
S. H. Woodward ◽  
J. C. Moller ◽  
...  
Keyword(s):  
Thin Film ◽  
Heat Flux ◽  
Design Flow ◽  
Suction Surface ◽  
Stagnation Region ◽  
Time Resolved ◽  
Analysis Technique ◽  
Typical Time ◽  
Flux Measurements ◽  
Dominant Frequencies

This paper presents a detailed description of an analysis technique and an application of this technique to obtain time-resolved heat flux for the blade of a Garrett TFE 731-2 hp full-stage rotating turbine. A shock tube is used as a short-duration source of heated air and platinum thin-film gages are used to obtain the heat-flux measurements. To obtain the heat-flux values from the thin-film gage temperature histories, a finite-difference procedure has been used to solve the heat equation, with variable thermal properties. The data acquisition and the data analysis procedures are described in detail and then their application is illustrated for three midspan locations on the blade. The selected locations are the geometric stagnation point, 32.7 percent wetted distance on the suction surface, and 85.5 percent wetted distance on the suction surface. For these measurements, the turbine was operating at the design flow function and very near 100 percent corrected speed. The vane–blade axial spacing was consistent with the engine operating configuration. The results demonstrate that the magnitude of the heat-flux fluctuation resulting from the vane–blade interaction is large by comparison with the time-averaged heat flux at all locations investigated. The magnitude of the fluctuation is greatest in the stagnation region and decreases with increasing wetted distance along the surface. A Fourier analysis by FFT of a portion of the heat-flux record illustrates that the dominant frequencies occur at the wake-cutting frequency and its harmonics.

On the Minimum Film Boiling Conditions for Spherical Geometries

1980 ◽  
Vol 102 (2) ◽  
pp. 335-341 ◽  
Author(s):  
F. S. Gunnerson ◽  
A. W. Cronenberg
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Flat Plate ◽  
Analytical Method ◽  
Boiling Point ◽  
Film Boiling ◽  
Heater Surface ◽  
Wide Range ◽  
Minimum Heat ◽  
Good Agreement

An analytical method is presented for predicting the minimum heater temperature and the minimum heat flux at the onset of film boiling for spherical and flat plate heaters in saturated and subcooled liquids. Consideration is given to a variety of factors known to affect the minimum film boiling point, including transient liquid-heater contact, interfacial wettability, heater geometry, and liquid subcooling. The theoretical correlations developed are the first known predictions for spherical geometries. A comparison of theory with experimental data indicates good agreement for the minimum heat flux and the minimum film boiling temperature. Results indicate that the minimum conditions may span a wide range depending upon the thermophysical nature of the heater surface and the boiling liquid.

Demonstrating the Use of Thin Film Gauges for Heat Flux Measurements in ICEs: Measurements on an Inlet Valve in Motored Operation

2016 ◽  
Author(s):  
Thomas De Cuyper ◽  
Sam Bracke ◽  
Jolien Lavens ◽  
Stijn Broekaert ◽  
Kam Chana ◽  
...  
Keyword(s):  
Thin Film ◽  
Heat Flux ◽  
Inlet Valve ◽  
Flux Measurements
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