Numerical Study of a Hemi-Spherical Cup in Steady, Unsteady, Laminar and Turbulent Flow Conditions With a Vent of Air at the Top Available to Purchase

In this paper, a 3D flow field around a bluff body (Hemi-spherical cup) in an incompressible fluid is modeled. On the top of the bluff body at its apex a vent of air is inserted. The vent ratio (Ratio of vent diameter to hemi-spherical cup diameter) at the apex of the body is varied. Four flow conditions are considered in this study. At first, the flow is taken to be steady and laminar, then unsteady and laminar, and later steady and turbulent, and finally unsteady and turbulent. Coefficients of drag, lift and pressure, and also the drag force with static pressure around the body are determined. From the four conditions investigate and comparing with the work done by Strickland, it can be seen that the steady and unsteady in turbulent condition gave better results. Also as the vent ratio increased, the drag coefficient decreased, and the highest drag obtained around 10 percent vent ratio.