Author: B. R. HallerPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The Effects of Film Cooling Upon the Aerodynamic Performance of Transonic Turbine Blades
Author: B. R. HallerExperimental and numerical investigations of film-cooling effects on the aerodynamic performance of transonic turbine blades, ASME 98-GT-546
Author: Martin F. UrbanPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Stockholm, Sweden, Jun 2-Jun 5, 1998.
Aerodynamic Loss Penalty Produced by Film Cooling Transonic Turbine Blades
Author: B. R. HallerStudies on Transonic Turbine with Film-Cooled Blades
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 123
Book Description
During the fourth 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. Surface Mach number and heat transfer rate distributions were determined for a reference transonic airfoil over a range of exit Mach numbers, for inlet incidence angle variation of + or - 15 deg. An evaluation and comparison of all cascade data collected so far was then conducted. Progress was also made in the investigation of the effects of unsteadiness on transonic airfoil aerodynamics and heat transfer.
Survey of Advantages and Problems Associated with Transpiration Cooling and Film Cooling of Gas-turbine Blades
Author: Ernst Rudolf Georg EckertPublisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 44
Book Description
Summary: Transpiration and film cooling promise to be effective methods of cooling gas-turbine blades; consequently, analytical and experimental investigations are being conducted to obtain a better understanding of these processes. This report serves as an introduction to these cooling methods, explains the physical processes, and surveys the information available for predicting blade temperatures and heat-transfer rates. In addition, the difficulties encountered in obtaining a uniform blade temperature are discussed, and the possibilities of correcting these difficulties are indicated. Air is the only coolant considered in the application of these cooling methods.
Aerodynamic Losses and Discharge Coefficients for a Transonic Turbine Blade with Film Cooling
Author: Kyle Leon LeePublisher:
ISBN:
Category : Gas-turbines
Languages : en
Pages : 190
Book Description
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.
An Investigation of the Aerodynamic Performance of Film Cooled Turbine Blades
Author: Eric Ralph McFarlandPublisher:
ISBN:
Category :
Languages : en
Pages : 234
Book Description
Effect of Incidence on Wall Heating Rates and Aerodynamics on a Film Cooled Transonic Turbine Blade
Author: Cengiz CamciPublisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 0
Book Description
This study investigates the influence of incidence on convective heat transfer to highly curved surfaces of a film-cooled turbine rotor blade. A computational study of free-stream inviscid aerodynamics without cooling at various incidences is followed by well-documented measured heat transfer data sets. The heat transfer experiments are discussed for cases with and without film cooling, performed under realistic gas turbine flow conditions in the short-duration heat transfer facility of the von Karman Institute for Fluid Dynamics. The precise location of the stagnation point and the iso-Mach number contours in the passage for each incidence (−10, 0, 10, +15 deg) are presented for a nominal exit Mach number of 0.94. The free-stream mass flow rate was kept constant for each experiment at different incidence levels. Three rows of compound angled discrete cooling holes are located near the leading edge in a showerhead configuration. Two rows of staggered discrete cooling holes are located on the suction side and a single row of cooling holes is located on the pressure side. The short-duration measurements of quantitative wall heat fluxes on nearly isothermal blade surfaces both in the presence and absence of coolant ejection are presented. The study indicated that the change of the position of the stagnation point strongly altered the aerodynamic behavior and convective heat transfer to the blade in approximately the first 30 percent of both the pressure side and the suction side in the presence and absence of film cooling. The immediate vicinity of the stagnation point was not significantly affected by changing incidence without cooling. Transitional behavior both on the suction surface and on the pressure surface was significantly influenced by the changes in approaching flow direction. Flow separation associated with incidence variations was also observed. Extremely low levels of the convective heat transfer coefficients were experienced near the regions where small separation bubbles are located.
Film Cooling Visualization and Heat Transfer on Transonic Turbine Blades
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 66
Book Description
This study is an investigation of the film cooling effectiveness and heat transfer coefficient of a two-dimensional turbine rotor blade in a linear transonic cascade. Experiments were performed in Virginia Tech's Cascade Wind Tunnel with an exit Mach number of 1.2 and an exit Reynolds number of 5 x 10 (exp 6) to simulate real engine flow conditions. The freestream and coolant flows were maintained at a total temperature ratio of 2 +0.4 and a total pressure ration of 1.04. The freestream turbulence was approximately 1%. There are six rows of staggered, discrete cooling holes on and near the leading edge of the blade in a showerhead configuration. Cooled air was used as the coolant. Experiments were performed with and without film cooling on the surface of the blade. The heat transfer coefficient was found to increase with the addition of film cooling an average of 14% overall and to a maximum of 26% at the first gauge location. The average film cooling effectiveness that suggest either a transition from a laminar to a turbulent film regime or the regime or the existence of three-dimensionality in the flow-field over the gauges.