Numerical Flow Simulation over a Flapping Wing Using Implicit RANS Solver

摘要

Numerical simulations are performed for the flow past a flapping wing to study the effect of reduced frequency on the thrust generation and propulsive efficiency. Time accurate solution has been obtained by using an implicit RANS solver IMPRANS that employs finite volume nodal point spatial discretization scheme with dual time stepping. The efficiency of the solver for making time-accurate computations is enhanced by implementing an implicit dual time stepping procedure. In this approach, an equivalent pseudo steady state problem is solved at each real time step using local time stepping. The algebraic eddy viscosity model due to Baldwin and Lomax is used for turbulence closure. The computations are carried out by varying the reduced frequencies (from k = 0.5 to k = 1.0) to study the effect on thrust generation and propulsive efficiency at Mach number 0.3 and Reynolds number 10~5. The results are obtained in the form of aerodynamic coefficients, thrust coefficient and propulsive efficiency.