Numerical analysis on the impact of axial grooves on vortex cooling behavior in gas turbine blade's leading edge

Abstract

In this article, a novel design for the vortex chamber with the axial grooves used for cooling the turbine blades leading edge is presented. The vortex chamber has nine tangential inlets that make a vortex in the chamber and an axial groove located along with the chamber. In addition to enhance the flow turbulence, these grooves cause an increasing heat transfer by cutting the thermal boundary layer and reformation. For this purpose, a 3D model based on Reynolds-averaged Navier–Stokes (RANS) equation was simulated in Ansys Fluent software. After comparing different turbulent models and experimental data, results showed Reynolds stress model (RSM) mode presents the best accuracy. Grooves with different sizes, positions, and numbers are used to investigate the vortex structure and the heat transfer mechanism. This study revealed that a chamber with grooves has a higher heat transfer in comparison with chambers without grooves. The best performance is achieved in a chamber with three grooves, where the average Nusselt number is increased by more than 4%. In this method, pressure difference between the inlet and outlet in the chamber with and without grooves are not very significant, and the highest friction factor happened in the case with three grooves.