Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 15
Book Description
Blade Heat Transfer Measurements and Predictions in a Transonic Turbine Cascade
Author: Blade Heat Transfer Measurements and Predictions in a Transonic Turbine Cascade
Author: P. W. GielBlade Heat Transfer Measurements and Prediction in a Transonic Turbine Cascade
Author: Blade heat transfer measurements and predictions in a transonic turbine cascade, ASME 99-GT-125
Author: P. W. GielPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Indianapolis, Indiana, June 7-10, 1999.
Endwall Heat Transfer Measurements in a Transonic Turbine Cascade
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 20
Book Description
Turbine blade endwall heat transfer measurements are given for a range of Reynolds and Mach numbers. Data were obtained for Reynolds numbers based on inlet conditions of 0.5 and 1.0 x 10(exp 6), for isentropic exit Mach numbers of 1.0 and 1.3, and for freestream turbulence intensities of 0.25% and 7.0%. Tests were conducted in a linear cascade at the NASA Lewis Transonic Turbine Blade Cascade Facility. The test article was a turbine rotor with 136 deg of turning and an axial chord of 12.7 cm. The large scale allowed for very detailed measurements of both flow field and surface phenomena. The intent of the work is to provide benchmark quality data for CFD code and model verification. The flow field in the cascade is highly three-dimensional as a result of thick boundary layers at the test section inlet. Endwall heat transfer data were obtained using a steady-state liquid crystal technique.
Heat Transfer Measurements and Predictions on a Power Generation Gas Turbine Blade
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 22
Book Description
Detailed heat transfer measurements and predictions are given for a power generation turbine rotor with 129 deg of nominal turning and an axial chord of 137 mm. Data were obtained for a set of four exit Reynolds numbers comprised of the design point of 628,000, -20%, +20%, and +40%. Three ideal exit pressure ratios were examined including the design point of 1.378, -10%, and +10%. Inlet incidence angles of 0 deg and +/-2 deg were also examined. Measurements were made in a linear cascade with highly three-dimensional blade passage flows that resulted from the high flow turning and thick inlet boundary layers. Inlet turbulence was generated with a blown square bar grid. The purpose of the work is the extension of three-dimensional predictive modeling capability for airfoil external heat transfer to engine specific conditions including blade shape, Reynolds numbers, and Mach numbers. Data were obtained by a steady-state technique using a thin-foil heater wrapped around a low thermal conductivity blade. Surface temperatures were measured using calibrated liquid crystals. The results show the effects of strong secondary vortical flows, laminar-to-turbulent transition, and also show good detail in the stagnation region.
Three-Dimensional Flow Field Measurements in a Transonic Turbine Cascade
Author: P. W. GeilPublisher:
ISBN:
Category :
Languages : en
Pages : 20
Book Description
Presented at the International Gas Turbine and Aeroengine Congress & Exhibition Birmingham, UK - June 10-13, 1996.
Studies on Transonic Turbines with Film-Cooled Blades
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 109
Book Description
In the third year of the contract, further advances were made towards the goal of gathering the heat transfer and aerodynamics flow data necessary for a good understanding of the performance of film-cooled, highly-loaded, transonic turbine blading. The MIT cascade blowdown facility now fully operational was used in evaluating the heat transfer performance of the four blade profiles designed in the first year of the program. The results show that the level of turbulence is an important parameter in determining heat transfer in transonic cascades. It also shows that the heat transfer to the trailing edge of the blades is very high being about 75% of the heat transfer to the leading edge. A comparison of the Nusselt number calculated from heat transfer measurements with the Nusselt number obtained by a prediction method using the pressure distribution shows good correspondence. The variation of average Stanton number over a range of Mach numbers shows that the reference blade has the most superior heat transfer performance. Preliminary data has been obtained on the off-design performance of the blades and full scale tests are underway. Comparative studies show that about 21% less heat needs to be taken out by internal cooling if one stage of a transonic turbine is used to replace two moderately loaded subsonic stages which produce the same output, have the same inlet stagnation conditions, have the same mass flow and the same tip speed. This demonstrates one of the potential advantages of transonic turbines.
Experimental and Numerical Studies of Unsteady Heat Transfer in a Transonic Turbine
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The effects of a shock wave passing through a blade passage on surface heat transfer to turbine blades were measured experimentally. The experiments were performed in a transonic linear cascade which matched engine Reynolds number, Mach number, and shock strength. Unsteady heat flux measurements were made with Heat Flux Microsensors on both the pressure and suction surfaces of a single blade passage. Unsteady static pressure measurements were made using Kulite pressure transducers on the blade surface and end wails of the cascade. The experiments were conducted in a stationary linear cascade of blades with heated transonic air flow using a shock tube to introduce shock waves into the cascade. A time-resolved model based on conduction in the gas was found to accurately predict heat transfer due to shock heating measured during experimental tests without flow. The model under-predicted the experimental results with flow, however, by a factor of three. The heat transfer increase resulting from shock passing in heated flow averaged over 200 us (typical blade passing period) was found to be a maximum of 60% on the pressure surface near the leading edge. Based on experimental results at different flow temperatures, it was determined that shock heating has the primary effect on heat transfer, while heat transfer increase due to boundary layer disturbance is small.
Endwall Heat Transfer Measurements in a Transonic Turbine Cascade
Author: P. W. GielPublisher:
ISBN:
Category : Heat
Languages : en
Pages : 15
Book Description
Turbine blade endwall heat transfer measurements are given for a range of Reynolds and Mach numbers. Data were obtained for Reynolds numbers based on inlet conditions of 0.5 and 1.0 x 10(exp 6), for isentropic exit Mach numbers of 1.0 and 1.3, and for freestream turbulence intensities of 0.25% and 7.0%. Tests were conducted in a linear cascade at the NASA Lewis Transonic Turbine Blade Cascade Facility. The test article was a turbine rotor with 136 deg of turning and an axial chord of 12.7 cm. The large scale allowed for very detailed measurements of both flow field and surface phenomena. The intent of the work is to provide benchmark quality data for CFD code and model verification. The flow field in the cascade is highly three-dimensional as a result of thick boundary layers at the test section inlet. Endwall heat transfer data were obtained using a steady-state liquid crystal technique.