Numerical Computation of Flow Past a Rectangular Cylinder Placed at Different Ground Clearances from a Fixed Wall

Abstract

An explicit Navier Stokes finite volume solver has been developed for calculation of flow past rectangular cylinders varying clearances from fixed ground wall. The governing equations are solved in primitive variables on a non-uniform staggered grid. The code was tested for unconfined flow past a square cylinder at various Reynolds numbers. Confined flow past a square cylinder with two different blockage ratios of l/4 and 1/6 was computed at Reynolds number 1000. Subsequently flow past rectangular cylinders of two different aspect ratios, namely, 1.0 and 2.0 have been investigated at different non dimensional ground clearances ranging from 1.0 to 5.5 at three different Reynolds numbers, namely, 250, 500 and 1000. It is found that drag increases and life becomes negative as the ground clearance decreases. The Strouhal number increases with decrease in ground clearance. Vortex shedding was observed for different combinations of aspect ratios, ground clearances and Reynolds numbers that were studied.