Author: Brian M. T. TangPublisher:
ISBN:
Category : Gas-turbines
Languages : en
Pages : 0
Book Description
Unshrouded Turbine Blade Tip Heat Transfer and Film Cooling
Author: Brian M. T. TangPublisher:
ISBN:
Category : Gas-turbines
Languages : en
Pages : 0
Book Description
Gas Turbine Blade Tip and Near Tip Heat Transfer with Film Cooling
Author: Gregory KramerGas Turbine Blade Film Cooling and Blade Tip Heat Transfer
Author: Shuye TengMeasurement and Analysis of Gas Turbine Blade Tip Heat Transfer and Film Cooling
Author: Jae Su KwakSurvey 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.
A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models
Author: Ali A. AmeriGas Turbine Blade Cooling
Author: Chaitanya D GhodkePublisher: SAE International
ISBN: 0768095026
Category : Technology & Engineering
Languages : en
Pages : 238
Book Description
Gas turbines play an extremely important role in fulfilling a variety of power needs and are mainly used for power generation and propulsion applications. The performance and efficiency of gas turbine engines are to a large extent dependent on turbine rotor inlet temperatures: typically, the hotter the better. In gas turbines, the combustion temperature and the fuel efficiency are limited by the heat transfer properties of the turbine blades. However, in pushing the limits of hot gas temperatures while preventing the melting of blade components in high-pressure turbines, the use of effective cooling technologies is critical. Increasing the turbine inlet temperature also increases heat transferred to the turbine blade, and it is possible that the operating temperature could reach far above permissible metal temperature. In such cases, insufficient cooling of turbine blades results in excessive thermal stress on the blades causing premature blade failure. This may bring hazards to the engine's safe operation. Gas Turbine Blade Cooling, edited by Dr. Chaitanya D. Ghodke, offers 10 handpicked SAE International's technical papers, which identify key aspects of turbine blade cooling and help readers understand how this process can improve the performance of turbine hardware.
Turbine Blade Tip Film Cooling Measurements
Author: Dean Andrew WardPublisher:
ISBN:
Category : Gas-turbines
Languages : en
Pages : 332
Book Description
Investigations of Flow and Film Cooling on Turbine Blade Edge Regions
Author: Huitao YangPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The inlet temperature of modern gas turbine engines has been increased to achieve higher thermal efficiency and increased output. The blade edge regions, including the blade tip, the leading edge, and the platform, are exposed to the most extreme heat loads, and therefore, must be adequately cooled to maintain safety. For the blade tip, there is tip leakage flow due to the pressure gradient across the tip. This leakage flow not only reduces the blade aerodynamic performance, but also yields a high heat load due to the thin boundary layer and high speed. Various tip configurations, such as plane tip, double side squealer tip, and single suction side squealer tip, have been studied to find which one is the best configuration to reduce the tip leakage flow and the heat load. In addition to the flow and heat transfer on the blade tip, film cooling with various arrangements, including camber line, upstream, and two row configurations, have been studied. Besides these cases of low inlet/outlet pressure ratio, low temperature, non-rotating, the high inlet/outlet pressure ratio, high temperature, and rotating cases have been investigated, since they are closer to real turbine working conditions. The leading edge of the rotor blade experiences high heat transfer because of the stagnation flow. Film cooling on the rotor leading edge in a 11/2 turbine stage has been numerically studied for the designand off-design conditions. Simulations find that the increasing rotating speed shifts the stagnation line from the pressure side, to the leading edge and the suction side, while film cooling protection moves in the reverse direction with decreasing cooling effectiveness. Film cooling brings a high unsteady intensity of the heat transfer coefficient, especially on the suction side. The unsteady intensity of film cooling effectiveness is higher than that of the heat transfer coefficient. The film cooling on the rotor platform has gained significant attention due to the usage of low-aspect ratio and low-solidity turbine designs. Film cooling and its heat transfer are strongly influenced by the secondary flow of the end-wall and the stator-rotor interaction. Numerical predictions have been performed for the film cooling on the rotating platform of a whole turbine stage. The design conditions yield a high cooling effectiveness and decrease the cooling effectiveness unsteady intensity, while the high rpm condition dramatically reduces the film cooling effectiveness. High purge flow rates provide a better cooling protection. In addition, the impact of the turbine work process on film cooling effectiveness and heat transfer coefficient has been investigated. The overall cooling effectiveness shows a higher value than the adiabatic effectiveness does.
A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781721189052
Category :
Languages : en
Pages : 26
Book Description
A computational study has been performed to predict the distribution of convective heat transfer coefficient on a simulated blade tip with cooling holes. The purpose of the examination was to assess the ability of a three-dimensional Reynolds-averaged Navier-Stokes solver to predict the rate of tip heat transfer and the distribution of cooling effectiveness. To this end, the simulation of tip clearance flow with blowing of Kim and Metzger was used. The agreement of the computed effectiveness with the data was quite good. The agreement with the heat transfer coefficient was not as good but improved away from the cooling holes. Numerical flow visualization showed that the uniformity of wetting of the surface by the film cooling jet is helped by the reverse flow due to edge separation of the main flow. Ameri, A. A. and Rigby, D. L. Glenn Research Center NASA/CR-1999-209165, NAS 1.26:209165, E-11756