Numerical analysis of ventilated cavity flow over a 2-D wall mounted fence

Ventilated cavity flow over a 2-D wall mounted fence is numerically investigated using a viscous approach. An implicit unsteady compressible solver was used with a RANS k - omega) SST turbulence model and VOF approach to capture the cavity interface. The simulations were carried out for a fixed fence height based Froude number and constant outlet pressure. Cavity topology, wall pressure distributions and the resulting hydrodynamic forces were determined as a function of ventilation rate, degree of fence immersion in the oncoming wall boundary layer and degree of confinement of the flow domain. It was found that with an increase in ventilation rate, lift increases and drag decreases resulting in a greater hydrodynamic efficiency (lift to drag ratio) of the fence-wall system. With increase in immersion of the fence in the boundary layer, both lift and drag decreased, while the lift to drag ratio increased. Variation in the degree of confinement had a large influence on the flow, with the reduction in lift and hydrodynamic efficiency observed for the more confined conditions.