DEVELOPMENT OF A COMPUTER CODE TO STUDY AND ANALYZE DIFFERENT TECHNIQUES EMPLOYED FOR TURBINE COOLING

Abstract

The distribution of temperature for a turbine blade is highly important to be determined so that we can avoid excessive high temperatures of the blade and we can determine its temperature gradients. The temperature distribution was predicted by the use of a unique technique which is known as finite difference technique. This technique involves grid generation and transformation techniques. The two-dimensional steady state conduction equation was used on the internal nodes of the mesh to get the desired temperature distribution. Whereas for all the nodes on the surface (inner and outer), we used the forced convection heat transfer equation. For the determination of convective heat transfer coefficient, we determined its Nusselt Number. We established a computer program for the solution of this problem. MATLAB was used to get the temperature distribution about the turbine blades. In MATLAB, certain different cooling techniques were analyzed and plotted first separately and then comparatively against each other. There are several cases for the thermal analysis of the blade, out of which we devised three cases for the present study of the turbine blades. These three cases require the internal as well as the external boundary conditions. The results of our study indicated that the best cooling method for the turbine blades has been obtained when we use the third case. The third case is when the blades are cooled by the techniques of impingement cooling technique and film cooling technique. We found that when the turbine blade was cooled using film cooling, the temperature drop of 170K was obtained.