Effects of Fluid Flow Characteristics and Heat Transfer of Integrated Impingement Cooling Structure for Micro Gas Turbine

Abstract

Gas turbine is one of the important sources of energy which combust a combination of fuel and compress air to produce a mechanical work that will be converted into electrical energy. Efficiency of gas turbine can be increased by raising the Turbine Inlet Temperature (TIT). The problem is current trend of TIT already exceed the allowable melting point temperature of metal blade material. The current turbine blade can withstand its high temperature by adding jet impingement cooling structure into turbine blade. The purpose of this research is to investigate the effect of combination two different stand-off distance ratio, Y/D towards the heat transfer coefficient of the target plate by using Ansys FLUENT Computational Fluid Dynamics (CFD). Combination of stand-off distance ratio, Y/D = 1.5&3.0 gave 2nd highest heat transfer coefficient on the target plate next to the original stand-off distance ratio, Y/D = 1.5 with only a slightly different in value. By combining two different stand-off distance ratio, Y/D in a set of arrays, it can affect the heat transfer coefficient on the target plate. It seems that the combination of stand-off distance may improve the performance of heat transfer coefficient of turbine blade that have relatively lower heat transfer coefficient and may be detrimental to the performance of heat transfer coefficient that have a relatively high heat transfer coefficient.