An Experimental Investigation of Film Cooling Performance of Louver Scheme

Abstract

The experimental investigation of the film cooling performance of louver schemes using Thermochromic Liquid Crystal technique is presented in this paper. The louver scheme allows the cooling flow to pass through a bend and impinges with the blade material, which then exits to the outer surface of the aerofoil through the film cooling hole. The cooling performance for the louver scheme was analyzed across blowing ratios of 0.5 to 1.5 at a density ratio of 0.94. The results showed that the louver scheme enhances the local and the average film cooling performances in terms of film cooling effectiveness, and net heat flux reduction better than other published film hole configurations. As well, it provides a widely spread of the secondary flow extensively over the downstream surface, thus, it enhances the lateral film cooling performance. Moreover, the louver scheme produces a lower heat transfer coefficient ratio than other film hole geometries at low and high blowing ratios. As a result, the louver scheme is expected to reduce the gas turbine airfoil’s outer surface temperature and provides superior cooling performance which increases airfoil life time.