Study of Gas Turbine Blade Impingement Cooling

Gas turbine engines are being used in most of land based power plant. The
increasing demand for energy has lead scientists and researchers to enhance the
performance of the gas turbine engines. High turbine inlet temperatures are required
to obtain high thermal efficiency and thus higher power output can be produced.
Turbine blade could experience high thermal stress due to limitation of its material
physical properties. A lot of studies had been carried out to solve this problem such
as by developing new material for turbine blade. One of the most effective solutions
is to introduce the cooling process in the turbine blade itself. The main focus of this
project is to study the heat transfer and temperature profile along the turbine blade
surface while the blade is cooled internally (impingement cooling). To observe the
cooling process in the gas turbine, a turbine blade geometry model has been created
using preprocessor software called GAMBIT. FLUENT software is used to simulate
the cooling process of the turbine blade. The simulation result is finally being
validated by using published data. The results comprise of the temperature
distribution along the surface ofthe turbine blade and the temperature distribution on
the surface of cooling passages. Temperature distribution on the previously
mentioned surfaces can be studied by observing the temperature contour which is
generated by FLUENT. The turbine blade is convectively cooled by the compressed
air that is bled from the fourteenth stage compressor. It is indicated that the
temperature of the turbine blade in the hot gas mainstream has been decreased during
operation. This research has proven that the cooling process of the turbine blade
occurs by the presence of the cooling air which flows through the cooling passages.