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

Abstract

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 β. Simulations are carried out by solving 3D RANS equations coupled with the standard k-ω turbulence model. Cooling performance for vortex chambers under different β, the inlet to target wall temperature ratio σ 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 β, which leads to a superior flow and heat transfer performance for the vortex chamber with higher β. The cooling air velocity and heat transfer intensity increase with the increasing σ, 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 β > 0°, presents more intense heat transfer and lower aerodynamic loss under the same Re and σ.