Numerical Simulation of Combined (Impingement/Film) Cooling Technique

The present paper describes a three-dimensional Finite Volume numerical simulation of flow and heat transfer in a combined cooling technique. The combined (impingement/film) cooling technique is used extensively in modern gas turbine engines for cooling of the hot gas-path components such as the turbine stator inner band. The governing equations are the fully elliptic, Reynolds-averaged Navier-Stokes equations. The SIMPLE algorithm is employed to correct the pressure term. The second order upwind scheme is used to discretize the convection terms. The (k- /SST) turbulence model is applied for the flow simulation. The mesh used is the body-fitted, multi-block grid system. Results on the variations of velocity and temperature profiles with geometrical parameters, at a fixed blowing rate ratio, for the combined cooling technique are presented. Comparisons of the present results on adiabatic cooling effectiveness for either 0 f the two cooling methods and also for the combined technique with the available experimental film cooling and numerical impingement cooling data indicate that the cooling effectiveness for the combined cooling is considerably enhanced