Numerical simulation on effects of film hole geometry and mass flow on vortex cooling behavior for gas turbine blade leading edge

The vortex chamber model with film holes is established to investigate the effect of film holes on vortex cooling in gas turbine blade leading edge. The 3D viscous steady Reynolds Averaged Navier-Stokes (RANS) equations and the standard k-omega model are utilized for numerical computation. Results show that the existence of film holes has a strong disturbance on the internal flow, which increases the upstream velocity of film holes and decreases the downstream velocity. Meanwhile, the heat transfer intensity is enhanced by 5.2% compared to the case without film holes. The pressure coefficient presents a fluctuant decrease for all cases. However, an increase in circumferential angle contributes to a decrease in pressure coefficient. The circumferential angle at 90 is the most suitable considering both average heat transfer coefficient and Nusselt number distribution. When the diameter ratio of film holes increases to 0.1, it has the highest heat transfer intensity. As the mass flow of film holes increases, the mainstream velocity, the averaged pressure coefficient C-ps and the globally averaged Nusselt number Nu(a) will decrease. (C) 2016 Elsevier Ltd. All rights reserved.