Numerical simulation of incompressible laminar flow over three-dimensional rectangular cavities

This paper presents results of investigations of unsteady incompressible flow past three-dimensional cavities, where there is a complex interaction between the external flow and the recirculating flow inside the cavity. A computational fluid dynamics approach is used in the study. The simulation is based on the solution of the unsteady Navier-Stokes equations for three-dimensional incompressible flow by using finite difference schemes. The cavity is assumed to be rectangular in geometry, and the flow is assumed to be laminar Typical results of computation are presented, showing the effects of the Reynolds number cavity geometry, and inflow condition on the cavity flow fields. The results show that high Reynolds numbers, with deep cavity and shallow cavity flows can become unsteady with Kelvin-Helmholtz instability oscillations and exhibiting a three-dimensional nature, with Taylor-Gortler longitudinal vortices on the floor and longitudinal vortex structures on the shear layer At moderate Reynolds numbers the shallow cavity flow is more stable than deep cavity flows. For a given Reynolds number the flow structure is affected by the thickness of the inflow boundary layer with a significant interaction between the external flow and the recirculating flow inside the cavity.