A numerical simulation of an incompressible cavity flow is conducted. Two dimensional Navier-Stokes equations are integrated using the staggered grid and a finite volume method with C-QUICK scheme for spatial derivatives and fully implicit scheme for the time derivative. Simple-C algorithm is employed to solve the pressure field.
We investigate the characteristics of cavity flow with respect to three variables : the ratio of length to depth(L/D), the ratio of depth to boundary layer thickness at upstream edge(D/δ) and the Reynolds number based on depth($Re_D$). The range of the Reynolds number is from 2639 to 20000. As the values of L/D and $Re_D$ increases, the flow became more unstable and the velocity fluctuation get larger. When the boundary layer thickness is thicker, the flow is found to be more stable. We confirm that the third eddy in the cavity plays important roles in the flow stability.
A series of open loop control with blowing and suction is carried out to reduce the fluctuation magnitude of cavity flow in shear layer mode. Control parameters are the control frequency, the phase and the control flow direction. The effects of these parameters are investigated with respect to two control points.
It is found that the control with its velocity in -45° direction at a point below the upstream edge is most effective.
