Effects of aerodynamic parameters on steam vortex cooling behavior for gas turbine blade leading edge

Abstract

Three-dimensional Reynolds-averaged Navier–Stokes equations are applied to further explore steam vortex cooling mechanism in gas turbine blade leading edge. Grid independence analysis and turbulence model validation are carried out to determine the proper grid dimension and turbulence model for simulations. Influences of Reynolds number and temperature ratio on steam vortex cooling flow and heat transfer behavior for the blade leading edge are investigated. Heat transfer and friction correlations for steam vortex cooling are achieved on the basis of numerical data. Results show that radial convection is generated due to violent rotational motion and uneven density distribution, contributing to heat transfer enhancement. For the sake of increasing steam velocity, the obvious increase in heat transfer intensity and decrease in friction coefficient are observed with the increasing Reynolds number. When the temperature ratio increases, the heat transfer intensity decreases slightly and the friction coefficient decreases significantly. The thermal performance increases with the increasing Reynolds number and the decreasing temperature ratio. Compared with calculating results, the heat transfer and friction correlations can predict steam vortex cooling characteristics accurately.