Flow Physics behind the Effects of Leading-edge Protuberances on the Airfoil Aerodynamic Performance

Abstract

This paper presents a numerical investigation of the flow physics behind the effects of leading-edge protuberances on the airfoil aerodynamic performance utilizing vortex dynamic method. An improved delayed detached eddy simulation (IDDES) method was adopted and validated through the comparisons with experimental results. Utilizing the IDDES scheme, together with vortex dynamic analysis, investigations were focused on the attached and post-stall regions, respectively. It was found that, within the attached region, the generation and development of the dominant diffused spanwise vortex rings over tubercled airfoil was responsible for the subsequent airfoil performance; within the post-stall region, the impaired flow detachment around both peak and trough sections of tubercles, due to the enhanced momentum injection by the strong streamwise vortices, resulted in better airfoil aerodynamic performance.