M. J. Vafaei Rostami1,∗,†, M. Saghafian1,‡, A. Sedaghat1,‡ and Mo. Miansari2, Numerical investigation of turbulent flow over a stationary and oscillatory NACA0012 airfoil using overset grids method, Int. J. Numer. Meth. Fluids 2011; 67:135–154.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
Int. J. Numer. Meth. Fluids 2011; 67:135–154
Published online 20 April 2010 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/fld.2332
Numerical investigation of turbulent flow over a stationary and oscillatory NACA0012 airfoil using overset grids method
M. J. Vafaei Rostami1,∗,†, M. Saghafian1,‡, A. Sedaghat1,‡ and Mo. Miansari2
1Mechanical Engineering Department, Isfahan University of Technology, Isfahan, Iran
2Mechanical Engineering Department, Babol Noushirvani University of Technology, Babol, Iran
In 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.
Received 23 July 2009; Revised 16 February 2010; Accepted 17 February 2010
KEY WORDS: stall; oscillatory airfoil; flow patterns; linear and nonlinear k–ε models; overset grids