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.

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.

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.

Time-Resolved Heat Transfer and Surface Pressure Measurements for a Fully Cooled Transonic Turbine Stage

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Jeremy B. Nickol ◽  
Randall M. Mathison ◽  
Malak F. Malak ◽  
Rajiv Rana ◽  
Jong S. Liu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Field ◽  
Surface Pressure ◽  
High Frequency ◽  
Gas Turbines ◽  
Pressure Measurements ◽  
Turbine Stage ◽  
Cooling Flow ◽  
Blade Cooling

The flow field in axial gas turbines is driven by strong unsteady interactions between stationary and moving components. While time-averaged measurements can highlight many important flow features, developing a deeper understanding of the complicated flows present in high-speed turbomachinery requires time-accurate measurements that capture this unsteady behavior. Toward this end, time-accurate measurements are presented for a fully cooled transonic high-pressure turbine stage operating at design-corrected conditions. The turbine is run in a short-duration blowdown facility with uniform, radial, and hot streak vane-inlet temperature profiles as well as various amounts of cooling flow. High-frequency response surface pressure and heat-flux instrumentation installed in the rotating blade row, stator vane row, and stationary outer shroud provide detailed measurements of the flow behavior for this stage. Previous papers have reported the time-averaged results from this experiment, but this paper focuses on the strong unsteady phenomena that are observed. Heat-flux measurements from double-sided heat-flux gauges (HFGs) cover three spanwise locations on the blade pressure and suction surfaces. In addition, there are two instrumented blades with the cooling holes blocked to isolate the effect of just blade cooling. The stage can be run with the vane and blade cooling flow either on or off. High-frequency pressure measurements provide a picture of the unsteady aerodynamics on the vane and blade airfoil surfaces, as well as inside the serpentine coolant supply passages of the blade. A time-accurate computational fluid dynamics (CFD) simulation is also run to predict the blade surface pressure and heat-flux, and comparisons between prediction and measurement are given. It is found that unsteady variations in heat-flux and pressure are stronger at low to midspan and weaker at high span, likely due to the impact of secondary flows such as the tip leakage flow. Away from the tip, it is seen that the unsteady fluctuations in pressure and heat-flux are mostly in phase with each other on the suction side, but there is some deviation on the pressure side. The flow field is ultimately shown to be highly three-dimensional, as the movement of high heat transfer regions can be traced in both the chord and spanwise directions. These measurements provide a unique picture of the unsteady flow physics of a rotating turbine, and efforts to better understand and model these time-varying flows have the potential to change the way we think about even the time-averaged flow characteristics.

Phase-Resolved Surface Pressure and Heat-Transfer Measurements on the Blade of a Two-Stage Turbine

1995 ◽  
Vol 117 (4) ◽  
pp. 653-658 ◽  
Author(s):  
M. G. Dunn ◽  
C. W. Haldeman
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Pressure ◽  
Space Shuttle ◽  
Pressure Measurements ◽  
Two Stage ◽  
Blade Row ◽  
Flux Measurements ◽  
Main Engine ◽  
Unsteady Pressure Measurements

Phase-resolved surface pressure, and unsteady pressure measurements are reported for the first-stage blade row of the Space Shuttle Main Engine two-stage fuel-side turbine. Measurements were made at 10, 50, and 90 percent span on both the pressure and suction surfaces of the blade. Phase-resolved and unsteady heat-flux measurements are also reported.

Time-Resolved Heat Transfer and Surface Pressure Measurements for a Fully-Cooled Transonic Turbine Stage

2014 ◽  
Author(s):  
Jeremy B. Nickol ◽  
Randall M. Mathison ◽  
Malak F. Malak ◽  
Rajiv Rana ◽  
Jong S. Liu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Field ◽  
Surface Pressure ◽  
High Frequency ◽  
Gas Turbines ◽  
Pressure Measurements ◽  
Turbine Stage ◽  
Cooling Flow ◽  
Blade Cooling

The flow field in axial gas turbines is driven by strong unsteady interactions between stationary and moving components. While time-averaged measurements can highlight many important flow features, developing a deeper understanding of the complicated flows present in high-speed turbomachinery requires time-accurate measurements that capture this unsteady behavior. Towards this end, time-accurate measurements are presented for a fully cooled transonic high-pressure turbine stage operating at design-corrected conditions. The turbine is run in a short-duration blowdown facility with uniform, radial, and hot streak vane-inlet temperature profiles as well as various amounts of cooling flow. High frequency response surface-pressure and heat-flux instrumentation installed in the rotating blade row, stator vane row, and stationary outer shroud provide detailed measurements of the flow behavior for this stage. Previous papers by Haldeman et al. [1, 2] have reported the time-averaged results from this experiment, but this paper focuses on the strong unsteady phenomena that are observed. Heat-flux measurements from double-sided heat-flux gauges cover three span-wise locations on the blade pressure and suction surfaces. In addition, there are two instrumented blades with the cooling holes blocked to isolate the effect of just blade cooling. The stage can be run with the vane and blade cooling flow either on or off. High-frequency pressure measurements provide a picture of the unsteady aerodynamics on the vane and blade airfoil surfaces, as well as inside the serpentine coolant supply passages of the blade. A time-accurate CFD simulation is also run to predict the blade surface pressure and heat-flux, and comparisons between prediction and measurement are given. It is found that unsteady variations in heat-flux and pressure are stronger at low to mid-span and weaker at high span, likely due to the impact of secondary flows such as the tip leakage flow. Away from the tip, it is seen that the unsteady fluctuations in pressure and heat-flux are mostly in-phase with each other on the suction side, but there is some deviation on the pressure side. The flow field is ultimately shown to be highly three-dimensional, as the movement of high heat transfer regions can be traced in both the chord and span-wise directions. These measurements provide a unique picture of the unsteady flow physics of a rotating turbine, and efforts to better understand and model these time-varying flows have the potential to change the way we think about even the time-averaged flow characteristics.

Influence of Vane/Blade Spacing on the Heat Flux for a Transonic Turbine

2000 ◽  
Vol 122 (4) ◽  
pp. 684-691 ◽  
Author(s):  
M. G. Dunn ◽  
C. W. Haldeman ◽  
R. S. Abhari ◽  
M. L. McMillan
Keyword(s):  
Heat Flux ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Heat Load ◽  
Two Dimensional ◽  
Turbine Stage ◽  
Flux Measurements ◽  
Analytical Research ◽  
Transonic Turbine ◽  
Measured Phase

An experimental and analytical research program determining the influence of vane/blade spacing on the vane and blade time-averaged and unsteady heat flux for a full-scale rotating turbine stage was performed. The turbine stage was operated at a transonic vane exit condition, with pressure and heat flux measurements obtained throughout the stage. This paper focuses on the midspan heat flux measurements for both the vane and blade at three vane/blade axial spacings: 20, 40, and 60 percent of vane axial chord. The time-averaged heat flux results for the vane and the blade are compared with predictions obtained using a two-dimensional, Reynolds-averaged multiblade row code, UNSFLO, developed by Giles (1984). The measured and predicted unsteady heat flux envelopes (as a function of vane/blade spacing) are also compared with predictions. For selected locations on the blade, a direct comparison between the measured phase-averaged surface pressure and the measured phase-averaged Nusselt number history is presented. At some locations along the surface the pressure and the heat flux are shown to be in phase, but at other locations they are not. The influence of vane/blade spacing on the blade heat load was found to be small, and much less than the differences caused by changes in the Reynolds number during the experimental matrix. [S0889-504X(00)00904-1]

scholarly journals Eddy Covariance flux measurements with a weight-shift microlight aircraft

2012 ◽  
Vol 5 (2) ◽  
pp. 2591-2643 ◽  
Author(s):  
S. Metzger ◽  
W. Junkermann ◽  
M. Mauder ◽  
F. Beyrich ◽  
K. Butterbach-Bahl ◽  
...  
Keyword(s):  
Heat Flux ◽  
Eddy Covariance ◽  
Sensible Heat Flux ◽  
Flux Measurement ◽  
Wind Measurement ◽  
Airborne Measurements ◽  
Weight Shift ◽  
Flux Measurements ◽  
Good Agreement

Abstract. The objective of this study is to assess the feasibility and quality of Eddy-Covariance flux measurements from a weight-shift microlight aircraft (WSMA). Firstly we investigate the precision of the wind measurement (σu,v≤ 0.09 m s−1, σw = 0.04 m s−1), the lynchpin of flux calculations from aircraft. From here the smallest resolvable changes in friction velocity (0.02 m s−1), and sensible- (5 W m−2) and latent (3 W m−2) heat flux are estimated. Secondly a seven-day flight campaign was performed near Lindenberg (Germany). Here we compare measurements of wind, temperature, humidity and respective fluxes between a tall tower and the WSMA. The maximum likelihood functional relationship (MLFR) between tower and WSMA measurements considers the random error in the data, and shows very good agreement of the scalar averages. The MLFRs for standard deviations (SDs, 2–34%) and fluxes (17–21%) indicate higher estimates of the airborne measurements compared to the tower. Considering the 99.5% confidence intervals the observed differences are not significant, with exception of the temperature SD. The comparison with a large-aperture scintillometer reveals lower sensible heat flux estimates at both, tower (−40–−25%) and WSMA (−25–0%). We relate the observed differences to (i) inconsistencies in the temperature and wind measurement at the tower and (ii) the measurement platforms differing abilities to capture contributions from non-propagating eddies. These findings encourage the use of WSMA as a low price and highly versatile flux measurement platform.

Heat-Flux and Pressure Measurements and Comparison With Prediction for a Low-Aspect-Ratio Turbine Stage

1986 ◽  
Vol 108 (1) ◽  
pp. 108-115 ◽  
Author(s):  
M. G. Dunn ◽  
H. L. Martin ◽  
M. J. Stanek
Keyword(s):  
Heat Flux ◽  
Aspect Ratio ◽  
Guide Vane ◽  
Test Time ◽  
Pressure Measurements ◽  
Detailed Measurement ◽  
Low Aspect Ratio ◽  
Long Run ◽  
Flux Measurements ◽  
Nozzle Guide

This paper describes the detailed measurement of heat-flux distributions for the nozzle guide vane (NGV) airfoil, the NGV hub and tip end walls, and the blade for the Garrett low-aspect-ratio turbine (LART) stage. A shock tube was used to generate a short-duration source of heated air and thin-film gages were used to obtain detailed heat-flux measurements. In addition to the heat-flux measurements, surface-pressure measurements were obtained on the vane pressure and suction surfaces and on the hub and tip endwalls. These pressure measurements are shown to compare favorably with those taken at the same locations but in a long-run time facility. The time-averaged heat-flux data were obtained by sampling the gage signals at a frequency of 20 kHz/channel and then averaging the output over the test time of the experiment. The results are presented as a function of location within the stage and are compared with the results of a local flat-plate prediction technique.

Endwall Performance of Outlet Guide Vane Cascades With Different Blade Loading Distributions

2008 ◽  
Author(s):  
Toyotaka Sonoda ◽  
Heinz-Adolf Schreiber ◽  
Toshiyuki Arima
Keyword(s):  
Guide Vane ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Wall Region ◽  
Pressure Gradients ◽  
Low Reynolds Numbers ◽  
Low Pressure Turbine ◽  
Controlled Diffusion ◽  
Low Reynolds ◽  
End Wall

As a part of an innovative aerodynamic design concept for a single stage low pressure turbine, a high turning outlet guide vane is required to remove the swirl from the hot gas. The airfoil of the vane is a highly loaded compressor airfoil that has to operate at very low Reynolds numbers (Re∼120,000). Recently published numerical design studies and experimental analysis on alternatively designed airfoils showed that blade profiles with an extreme front loaded pressure distribution are advantageous for low Reynolds number conditions. This paper experimentally and numerically discusses about the three-dimensional performance near the end-wall of two alternatively designed cascades, the end-wall performance of a baseline cascade with controlled diffusion airfoils (CDA) and a cascade with extreme front loaded airfoils. The results showed that although the end-wall pressure gradients are different, the characteristics of the secondary flow are very similar for both of the cascades. Both, experiment and numerical analysis showed that the losses close to the end-wall of the extreme front loaded airfoils are even lower in relation to those of the CDA airfoils. The flow mechanism on the superiority of the extreme front loaded airfoils around the end-wall region is discussed.

Sign in / Sign up

Export Citation Format

Share Document