Large eddy simulation applied to internal forced-convection cooling of gas-turbine blades

Heat transfer in an orthogonally rotating rib-roughened square duct was numerically simulated by using the fourth order finite difference method. In order to investigate the effect of the Coriolis form on the turbulence, the large eddy simulation was performed with a dynamic subgrid scale model. The present results clearly showed the high correlation between shear stress and heat transfer coefficients in an instantaneous field. The rotation caused the larger peripheral variation both in shear stress and heat transfer. As compared to the stationary smooth duct case, the friction coefficient and the overall Nusselt number were increased by the factor of 5.7 and 2.1, respectively. In addition to these factors, the present numerical results agreed well with the experimentally observed characteristics.