Numerical simulation of incompressible viscous flow past a heaving airfoil

TLDR: In this article, numerical simulations of a heaving airfoil undergoing non-sinusoidal motions in an incompressible viscous flow are presented, and the wake patterns, thrust force coefficients, and propulsive efficiency at various values of non-dimensional heave velocity are computed.

Abstract: Numerical simulations of a heaving airfoil undergoing non-sinusoidal motions in an incompressible viscous flow is presented In particular, asymmetric sinusoidal motions, constant heave rate oscillations, and sinusoidal motions with a quiescent gap, are considered The wake patterns, thrust force coefficients, and propulsive efficiency at various values of non-dimensional heave velocity are computed These have been compared with those of corresponding sinusoidal heaving motions of the airfoil It is shown that for a given non-dimensional heave velocity and reduced frequency of oscillation, asymmetric sinusoidal motions give better thrust and propulsive efficiencies in comparison to pure harmonic motion On the other hand, constant rate heave motion do not compare favourably with harmonic motion A train of sinusoidal pulses separated by a quiescent gap compares favourably with a pure sinusoidal motion, but with the notable exception that the quiescent gap induces a discontinuity that induces large impulses to the wake pattern