Detached-Eddy Simulation of flow past a pitching NACA 0015 airfoil with pulsed actuation

摘要

This study conducted Detached-Eddy Simulations of the actively controlled flow over a 0.35 m chord NACA0015 airfoil with a chord Reynolds number of 1 million. Our results agreed well with experimental data at near-stall conditions, which indicated that the "Grey Area" problem in DES (Detached-Eddy Simulation) was addressed by using a newly proposed modification that can activate LES mode downstream the separation location while preserve it in free shear layers. Then the pulsed blowing actuation was used regarding the experimental settings. The flow-field around jet orifices was resolved, instead of the use of actuation boundary conditions. The results showed that flow separation can be delayed by excitation mechanisms through the orifices positioned at 30% of the chord length. To further reduce the strong unsteadiness introduced by excitation, a phase shift among jet orifices was applied and evaluated.