Study on the effect of number of film cooling rows on the thermal performance of gas turbine blade

This paper presents three dimensional (3d) numerical investigations on the effect of film cooling on the thermal behavior of gas turbine blades,using a commercial computational fluid dynamics (cfd) code. the 3d airfoil geometry of the blade which emulates the actual (a-4 skyhawk) blade is generated in the pre-processor (gambit). two cooling configurations namely 1) four rows film cooling with u-bend internal channel and 2) eight rows film cooling with u-bend internal channel,have been simulated to be transonic flow over a turbine blade with turbo-specific non-reflecting boundary conditions (nrbcs). turbulence is represented using the shear-stress transport (sst) model,and the flow is assumed to have a free-stream turbulence intensity of 9%. the heat transfer coefficient,total temperature distribution,static pressure and velocity vector are investigated. the effect of coolant injection pressure ratio (p r,ci) on temperature distribution is also investigated. the results show that heat transfer coefficient with film cooling is higher than that without film cooling. from the predicted temperature profile,it is observed that the blade with eight rows film cooling with u-bend internal channel shows better cooling performance than that with four rows. further,increase in p r,ci leads to reduction in temperature and moreover the lateral spreading facilitated the best coolant layer. © 2012 tibtd printed in turkey.