Numerical Investigation of Non-Stationary Parameters on Effective Phenomena of a Pitching Airfoil at Low Reynolds Number

Various applications of ornithopter have led to research interest in oscillation airfoils which affect on low Reynolds number flight, like; pitching oscillation, heaving oscillation and flapping of a wing. The purpose of this study is investigation of aerodynamic characteristics of NACA۰۰۱۲ airfoil with a simple harmonic pitching oscillation at zero and ۱۰ degrees of mean angle of attack. Therefore the effects of unstable parameters, including oscillation amplitude up to ۱۰ degrees, reduced frequency up to ۱.۰, center of oscillation up to ۶/۸ chord length, and Reynolds number up to ۵۰۰۰ have been studied numerically. A pressure based algorithm using a finite volume element method has been used to solve Navier-Stokes equations. According to results, variation of each studied parameters at mean angle of attack of ۰ degree do not cause significant changes in flow phenomena on airfoil but at mean angle of attack of ۱۰ degrees, changing in reduced frequency and specially Reynolds number cause variations in flow phenomena. These variations are because of “wake capturing” and/or “added mass” phenomena.

Keywords:

Oscillation amplitude , Center of oscillation , Reduced frequency , Pitching oscillation