Numerical Investigation of Two Double Swirl/Vortex Chamber Configurations for Turbine Blade Leading Edge Cooling

Abstract

The objective of this work is to numerically assess the cooling performance of two double swirl/vortex chamber configurations (DSC and M-DVC). The predictive capability of five turbulence models is critically evaluated on fine and good-quality mesh for impinging and swirling flows. The averaged second norm 2 L is employed to quantitatively measure the simulation error from each turbulence model compared to the experimental data. The RNG k  − turbulence model with enhanced wall treatment is found to be the most accurate and suitable for the simulation of impinging and swirling flows. Various key physical and dimensionless parameters, including thermal performance factor, turbulence kinetic energy and vorticity, are used to comparatively assess the cooling performance of DSC and M-DVC under the laboratory testing condition and the real operating condition at base load. The results reveal that DSC can enhance better heat transfer due to higher turbulence kinetic energy. Also, much more uniform Nusselt number distribution is obtained by DSC owing to more symmetric and uniformly distributed velocity and vorticity. With the real operating condition, DSC even performs much better than M-DVC.