Experimental and numerical study of turbulent heat transfer on a cylindrical pedestal

Abstract

Experimental data are presented of local surface heat transfer coefficients in a turbulent axisymmetric jet, impinging onto a cylindrical pedestal, mounted on a flat plate. The preheated wall transient method is applied with liquid crystals. Simulation results with standard two-equation turbulence models reveal strong deviations from the experimental data. Therefore, a two-equation turbulence model is used, incorporating effects from streamline curvature in the eddy viscosity and reducing turbulence production in stagnation flow regions through the dissipation rate transport equation and the turbulent viscosity. It is illustrated that this leads to accurate heat transfer predictions. For the turbulent heat transfer, the linear gradient diffusion hypothesis is applied. Heat transfer is examined on the pedestal top and side face, as well as on the plate. Different Reynolds numbers and nozzle–pedestal distances are considered.