Numerical Analysis of Effects of Leading-Edge Protuberances at Low Reynolds Number

摘要

This paper presents a numerical investigation of the aerodynamic performance of an airfoil with leading-edge protuberances within stall region at Reynolds number of 2 × 10~5. An IDDES (Improved Delayed Detached Eddy Simulation) method was developed based on a transition model through the modification of turbulence length and the limitation of intermittency factor and validated through quantitative comparison with experimental results. Utilizing the developed method, the vortex evolution and thus the physics of the dominant bi-periodic phenomenon were uncovered. In addition, the effects of bi-periodic flow patterns on aerodynamic forces were also investigated. It was found that bi-periodic phenomenon deteriorated the aerodynamic performance by the inducement of massive flow separation at leading edge. Moreover, the variations in the flow patterns led to little change in total lift coefficient around stall region.