Detached-eddy Simulation Of Flow Past A Pitching NACA 0015 Airfoil With Active Flow Control

The aircraft stall caused by flow separation limits the progress in aviation indus-try.The flow-separation-delay technique has been a hot research topic for years.So far,compared to the massively separated flow case,there are few researches on the ad-vanced numerical simulations of the shallow flow separation that occurs,e.g.on airfoil under near-stall condition as well as where the flow separation control is activated.This paper numerically simulated the actively controlled flow over a 0.35 m chord NACA0015 airfoil at an incidence angle of 11° and a chord Reynolds number of 1 mil-lion.First,the flow control methods were described in detail and classified according to their working mechanism.Then,by comparing the various characteristics of different numerical methods,it is found that to resolve such flow patterns benefits the IDDES(Delayed Detached Eddy Simulation)methods based on the SA turbulence model.Consequently,IDDES of the base flow as well as the excited cases were carried out.The synthetic jet and pulsed blowing actuations were applied in our work.The vor-tex shedding frequency for the base flow was obtained by spectrum analysis and DMD analysis.The pulse blowing improve the flow quality around the three-dimensional airfoil,i.e.the separation occurred downstream,resulting in the increase of lift-to-drag ratio.For the pulse blowing method,0.5 times vortex shedding frequency.five times external flow velocity and large phase shift show a positive optimal performance on flow separation control.