In CFD simulations of supersonic flows, where bleed through discrete holes is used to control boundary-layer profiles, resolving the flow through each bleed hole and the associated bleed plenum can require a prohibitively large number of grid points. In this study, two outflow boundary conditions (BCs) for bleed holes, referred to as bleed BCs, are evaluated by comparing with results from simulations that resolve the flow in each hole and plenum (DNS results). The two bleed BCs evaluated are (1) DNS-BC (specify normal velocity, W, in each hole based on DNS results and extrapolate all other variables), (2) Cd-BC (same as DNS-BC except W is calculated by using a discharge coefficient that gives the correct bleed rate). Both bleed BCs can discern the location and size of bleed holes because they are only applied on parts of the wall, where there is a hole. Results obtained show the Cd-BC to be able to predict accurately the pressure and Mach number profiles downstream of the bleed region by using only one grid point/cell for a normal hole and two grid points/cells for a 200 inclined hole. The qualitative features of the bleed process including the "barrier" shock can also be discerned. The Cd-BC is shown to be superior to porous-wall bleed BCs that do not take into consideration the location of the bleed holes.
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