Coherence of unsteady wake of periodically plunging airfoil

Unsteady flow past a plunging airfoil

This paper presents simulations of unsteady flow past a plunging airfoil using the highorder spectral difference (SD) method. Both third-order and fourth-order SD methods are used on unstructured quadrilateral grids. The vortex shedding pattern of an airfoil in an oscillating plunge motion becomes asymmetric at a sufficiently high frequency. The SD method is able to capture this effect and reve...

Aerodynamics of Low Reynolds Number Plunging Airfoil under Gusty Environment

Abstract It is known that plunging airfoil can produce both lift and thrust with certain combination of plunging amplitude and frequency. Motivated by our interest in micro air vehicles (MAVs), we utilize a NavierStokes equation solver to investigate the aerodynamics of a flapping airfoil. The roles of the plunging and pitching amplitude and frequency, and Strouhal number are studied. For a sym...

Airfoil Thickness Effects on the Thrust Generation of Plunging Airfoils

Anumerical study was conducted to investigate the effects of airfoil thickness on the thrust generation of plunging airfoils and to assess the contributions of pressure and viscous forces in flapping propulsion. A series of NACA symmetric airfoils with thickness ratio ranging from 4.0% to 20.0% of the airfoil chord length were used in the present study to undertake a same sinusoid plunging moti...

Plunging Airfoil Load Characteristics Equipped with Gurney Flap

Numerous experiments have been conducted on plunging Eppler 361 airfoil in a subsonic wind tunnel. The experimental tests involved measuring the surface pressure distribution over the airfoil at Re=1.5×105. The airfoil was equipped with Gurney flap(heights of 2.6, 3.3 and 5% chord) and plunged at 6cm amplitude. The unsteady aerodynamic loads were calculated from the surface pressure measurement...

Supercritical Flow over Unstalled Plunging Airfoil Computed by Euler Method