Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
Prediction of Film Cooling on Gas Turbine Airfoils
Author: An analytical prediction of the effects of film cooling on gas turbine blades
Author: Kevin Lloyd MillerPublisher:
ISBN:
Category : Gas-turbines
Languages : en
Pages : 278
Book Description
Gas Turbine Heat Transfer and Cooling Technology, Second Edition
Author: Je-Chin HanPublisher: CRC Press
ISBN: 1439855684
Category : Science
Languages : en
Pages : 892
Book Description
A comprehensive reference for engineers and researchers, Gas Turbine Heat Transfer and Cooling Technology, Second Edition has been completely revised and updated to reflect advances in the field made during the past ten years. The second edition retains the format that made the first edition so popular and adds new information mainly based on selected published papers in the open literature. See What’s New in the Second Edition: State-of-the-art cooling technologies such as advanced turbine blade film cooling and internal cooling Modern experimental methods for gas turbine heat transfer and cooling research Advanced computational models for gas turbine heat transfer and cooling performance predictions Suggestions for future research in this critical technology The book discusses the need for turbine cooling, gas turbine heat-transfer problems, and cooling methodology and covers turbine rotor and stator heat-transfer issues, including endwall and blade tip regions under engine conditions, as well as under simulated engine conditions. It then examines turbine rotor and stator blade film cooling and discusses the unsteady high free-stream turbulence effect on simulated cascade airfoils. From here, the book explores impingement cooling, rib-turbulent cooling, pin-fin cooling, and compound and new cooling techniques. It also highlights the effect of rotation on rotor coolant passage heat transfer. Coverage of experimental methods includes heat-transfer and mass-transfer techniques, liquid crystal thermography, optical techniques, as well as flow and thermal measurement techniques. The book concludes with discussions of governing equations and turbulence models and their applications for predicting turbine blade heat transfer and film cooling, and turbine blade internal cooling.
Aerodynamic Loss Models and Multi-dimensional Prediction of Discrete Hole Film Cooling on Gas Turbine Blades
Author: İlker TopçuoğluExperimental Measurement of Overall Effectiveness and Internal Coolant Temperatures for a Film Cooled Gas Turbine Airfoil with Internal Impingement Cooling
Author: Randall Paul WilliamsPublisher:
ISBN:
Category :
Languages : en
Pages : 258
Book Description
A scaled-up gas turbine vane model was constructed in such a way to achieve a Biot number (Bi) representative of an actual engine component, and experiments were performed to collect temperature data which may be used to validate computational fluid dynamics (CFD) codes used in the design of gas turbine cooling schemes. The physical model incorporated an internal impingement plate to provide cooling on the inner wall surface, and film cooling over the external surface was provided by a single row of holes located on the suction side of the vane. A single row of holes was chosen to simplify the operating condition and test geometry for the purpose of evaluating CFD predictions. Thermocouples were used to measure internal gas temperatures and internal surface temperatures over a range of coolant flow rates, while infra-red thermography was used to measure external surface temperatures. When Bi is matched to an actual engine component, these measured temperatures may be normalized relative to the coolant temperature and mainstream gas temperature to determine the overall cooling effectiveness, which will be representative of the real engine component. Measurements were made to evaluate the overall effectiveness resulting from internal impingement cooling alone, and then with both internal impingement cooling and external film cooling as the coolant flow rate was increased. As expected, with internal impingement cooling alone, both internal and external wall surfaces became colder as the coolant flow rate was increased. The addition of film cooling further increased the overall effectiveness, particularly at the lower and intermediate flow rates tested, but provided little benefit at the highest flow rates. An optimal jet momentum flux ratio of I=1.69 resulted in a peak overall effectiveness, although the film effectiveness was shown to be low under these conditions. The effect of increasing the coolant-to-mainstream density ratio was evaluated at one coolant flow rate and resulted in higher values of overall cooling effectiveness and normalized internal temperatures, throughout the model. Finally, a 1-dimensional heat transfer analysis was performed (using a resistance analogy) in which overall effectiveness with film cooling was predicted from measurements of film effectiveness and overall effectiveness without film cooling. This analysis tended to over-predict overall effectiveness, at the lowest values of the jet momentum flux ratio, while under-predicting it at the highest values.
Numerical Simulations of Leading Edge Film Cooling Flows for Gas Tubine Airfoils
Author: Cheryl A. MartinEvaluation of Film Cooling Superposition Method on the Suction Side of a Blade Model
Author: Christopher YoonPublisher:
ISBN:
Category :
Languages : en
Pages : 126
Book Description
Film cooling is often used for turbine airfoil cooling, and there are numerous studies of the performance of a single row of holes. Typically, blades and vanes in gas turbine engines have multiple rows of holes that interact. Consequently, there is a need to develop techniques to predict film cooling performance with multiple rows of holes. One of the method is to superposition single row cooling effectiveness to predict combined effectiveness. Although there have been many studies of superposition techniques with multiple rows of cylindrical holes, there have been very few in which shaped holes were used with a typical turbine airfoil model. In this study, film effectiveness was measured on the suction side of a turbine blade model using two rows of 7-7-7 shaped holes, with pitch to diameter ratio of 6, and the two rows were more than 40 diameters apart. Measurements were made with each row operating independently, which provided the experimental data for superposition predictions. These predictions were evaluated with effectiveness measurements with both rows operational. For these combined row tests, two different upstream blowing ratios and a wide range of downstream blowing ratios were selected. The superposition predictions were reasonably accurate when the upstream blowing ratio was high with a corresponding smaller film effectiveness downstream (due to jet separation). However, when the upstream coolant holes were operated at optimum blowing ratio with maximum film effectiveness downstream, the superposition analysis predicted film effectiveness levels slightly lower than actual levels. These results indicate that there was an interaction between jets that resulted in higher film effectiveness than what the superposition method had predicted
Studies of Gas Turbine Heat Transfer Airfoil Surface and End-Wall Cooling Effects
Author: E. R. EckertPublisher:
ISBN:
Category :
Languages : en
Pages : 58
Book Description
Research results on curved surface heat transfer, airfoil heat transfer, film cooling and end-wall heat transfer are presented. In particular these studies focus on the recovery process of a turbulent boundary layer from curvature, heat transfer measurements and numerical prediction techniques of film-cooling on an adiabatic flat plate by injection through a single row of holes. Keywords: Heat transfer, Turbulence.
Heat Transfer in Gas Turbines
Author: Bengt SundénPublisher: Witpress
ISBN:
Category : Medical
Languages : en
Pages : 544
Book Description
This title presents and reflects current active research on various heat transfer topics and related phenomena in gas turbine systems. It begins with a general introduction to gas turbine heat transfer, before moving on to specific areas.
Analysis of Combined Convective and Film Cooling on an Existing Turbine Blade
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
To support gas turbine operators NLR is developing capabilities for life assessment of hot engine components. As a typical example the first rotor blades of the high pressure (HP) turbine of the F-lOO-PW-220 military turbofan will be discussed. For these blades tools have been developed to derive the blade temperature history from flight data obtained from F-16 missions. The resulting relative life consumption estimate should support the Royal Netherlands Air Force in their engine maintenance activities. The present paper describes the prediction method for the blade temperature based on reverse engineering. Input data are the flight data of the engine performance parameters and the geometry of the HP turbine blades and vanes including film cooling orifices. The engine performance parameters are converted in HP turbine entry and exit conditions by the NLR Gas Turbine Simulation Program (GSP) engine model. Next a Computational Fluid dynamics (CFD) tool is used to calculate the resulting flow field and heat transfer coefficients without film cooling. An engineering method is used to predict the internal cooling and the resulting film injection temperature. The film cooling efficiency is estimated and a finite element method (FEM) for heat conduction completes the analysis tool. The method is illustrated by results obtained for the engine design point.