Computational Study on Pressure Side Film Cooling and Flow Structure

A computational investigation is carried out to understand the film cooling performance and flow phenomenon on a pressure side of gas turbine airfoil. A specific geometry with multiple rows of cylindrical holes is considered on the pressure surface and opposite to which a flat surface is kept so as to avoid effect of imposed flow conditions. Meshing of the present model is done by using GAMBIT. Computations are carried out with K-epsilon Realizable model available in the commercial code FLUENT. The film cooling performance is discussed with flow structure followed by the effectiveness distribution on the pressure surface. The blowing ratio is varied from 0.4–2.4 and it is found that, at very low blowing ratio cases in the initial part of the pressure surface higher effectiveness values are observed but at higher blowing ratio these values become very low whereas close to the trailing edge side the effectiveness distribution is just the reverse. It was found that the optimum blowing ratio was close to unity where better flow and temperature distribution were observed.