الفهرس 
Mathematical modelOnly 14 pages are availabe for public view
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Abstract
The development of high performance aircraft engines and electric power generation systems requires gas turbines to be operated at high inlet gas temperatures. Under these operating conditions where the inlet gas temperatures are greater than the allowable metal-temperature limits, the turbine blades need to be protected to ensure their integrity. The nozzle guide blades in a gas turbine, located directly downstream of the combustion section, are particularly susceptible to thermal failure, with gas temperatures commonly reaching levels above component latent melting temperatures. An efficient cooling technique such as film cooling is therefore needed to protect the gas turbine blades. Film cooling is a technique used extensively in turbomachinery. In such a situation, cooling air is taken from the compressor and injected through single or multiple rows of holes into the high temperature boundary layer on the blade surface. Because the coolant represents a loss in the output power, the designer’s objective is, therefore, to minimize the coolant necessary to ensure adequate turbine life by an efficient blade cooling. The efficiency of this technique depends on several parameters, such as the injection blowing ratio, the density ratio, the mainstream turbulence intensity, the mainstream pressure gradient, the boundary layer thickness, the injection angle, spacing between holes as well as their arrangement and the blade geometry. The main objective of the present study is to perform theoretical approach for two different models of the first stage for both profiles VKI and C3X turbine blades cascade with a leading edge showerhead film-cooling arrangement. The governing equations for steady, two-dimensional, turbulent, compressible flow are integrated over arbitrary two-dimensional control volumes. The present computational model seeks to a realistic film-cooled turbine blade. The code is used to study the combination of film and convection cooling, while most of the theoretical studies considered isothermal blade surfaces in the thermal calculations over the blade surfaces.