Numerical investigation of turbulent flow over a stationary and oscillatory NACA0012 airfoil using overset grids method

Abstract

AbstractIn this numerical study, unsteady and incompressible turbulent flows have been considered around stationary and flapping NACA0012 airfoil. Overset grid technique is used in this work. Three turbulence models have been examined including the linear Launder–Sharma k–ε model, nonlinear Craft–Launder–Suga k–ε model and nonlinear Lien–Chen–Leschziner k–ε model.First, the flow field around a stationary airfoil is solved for validating purposes. The results reveal different capabilities of capturing separation angle of attack using linear and nonlinear models. Nonlinear models predict smaller stall angle compared with the linear ones.Second, the flow field around a plunging airfoil is considered at various angles of attack, reduced frequencies and different amplitudes. The results show that the effects of reduced frequency are highly significant. There are differences in aerodynamic forces and wake structures in the upstroke and the down stroke motions, because they are functions of the mean angle of attack, oscillation amplitude and reduced frequency. Copyright © 2010 John Wiley & Sons, Ltd.