Effects of film cooling hole locations on flow and heat transfer characteristics of impingement/effusion cooling at turbine blade leading edge

Abstract

In order to investigate the effects of the film cooling hole locations on the flow and heat transfer characteristics of the impingment/effusion cooling, the film cooling holes are established on a concave target channel with three inclined angle (0°, 30°, 60° between film cooling hole axis and jet hole axis). The film cooling holes are both in-line and staggered arranged with jet holes when the inclined angle is 30° and 60° and only staggered arranged when the inclined angle is 0°. The film extraction flow distributions, static pressure development, total pressure drop, overall averaged Nusselt number and combined thermal performance are compared among different cases. The development of vortex and cross flow inside the target channel in different cases are studied and compared. The span averaged Nusselt number, Nusselt number contour on the target surface and Nusselt number distribution at several cross sections are studied and compared. Results show that the location of the film cooling holes affects the flow distributions of the film extraction air and the flow development inside the target channel. The heat transfer performance inside the target channel is affected by the impinging effect and the development of the cross flow and vortices.