Study On Dynamic Stall Control Of Undulatory Airfoils

Active flow control for fish and mammals uses appendage or bodymusculature to modify the surrounding flow structure. It is reported thatcurvature of flexible bodies could change flow over the fluke surface toincrease the forces generated. Hence the high levels of maneuverabilitycould be obtained.Numerical investigations of the dynamic stall control for theundulatory airfoils based on the open scource code OpenFOAM areconducted. Chordwise deformation of NACA0012airfoil has beenimplemented by adding dynamic mesh boundary condition intoOpenFOAM and the relative boundary condition have been validated.OpenFOAM basic solver PimpleDyMFoam is used for turbulent flow anddynamic mesh simulations.The study is focused on the influence of the deformation on thesurrounding fluid field and the consequence on the production of liftforce. Comparisons of the effectiveness of pitching airfoils andundulatory airfoils on dynamic stall control are conducted. The effect ofvarious combinations of amplitude and reduced frequency is alsodiscussed in this paper. Results show the undulatory airfoils are betterthan the pitching airfoils on dynamic stall control.