Investigation of the vortex cooling flow and heat transfer behavior in variable cross-section vortex chambers for gas turbine blade leading edge

摘要

This paper numerically compares the flow and heat transfer behavior in a set of variable cross-section vortex chambers with the different vortex chamber draft angle beta. Simulations are carried out by solving 3D RANS equations coupled with the standard k-omega turbulence model. Cooling performance for vortex chambers under different beta, the inlet to target wall temperature ratio sigma and Reynolds number Re are compared in detail. Results indicate that flow and heat transfer behavior of vortex cooling in variable cross-section vortex chambers is distinctly different from that in the uniform cross-section vortex chamber. The heat transfer intensity increases and pressure drop and aerodynamic loss decrease with an increase in beta, which leads to a superior flow and heat transfer performance for the vortex chamber with higher beta. The cooling air velocity and heat transfer intensity increase with the increasing sigma, while aerodynamic loss decreases with the increasing temperature ratio. When Re increases, both of the pressure drop and heat transfer intensity increase. Compared with the uniform cross-section vortex chamber, the vortex chamber of beta > 0 degrees, presents more intense heat transfer and lower aerodynamic loss under the same Re and sigma.