Boundary-layer mass removal (bleed) through spanwise bands of holes on a surface is used to prevent or control separation in supersonic inlets. The rough wall algebraic turbulence model of Cebeci and Chang was added to both boundary-layer and Navier-Stokes analyses to simulate the overall effect of bleed on the growth of a boundary layer. Roughness values were determined for seven bleed configurations, a range of Mach numbers between 1.3-4, and bleed rates between zero and choked values. For the bleed experiments considered, the roughness was found to be a function of the fraction of the upstream boundary-layer mass flux removed. Choked bleed flow through holes at a low angle, with respect to the surface, minimized the roughness effect and gave the best improvement in the boundary-layer velocity distribution for separation control. NomenclatureA + = Van Driest parameter, 26 d ~ bleed hole diameter k = von Karman constant, 0.4 k s = equivalent sand grain roughness Lid -hole aspect ratio / = local turbulent length scale M = Mach number N = number of rows of bleed holes in bleed band P/POO = local static pressure/freestream static pressure R = roughness parameter, in. ulu e -ratio of local to freestream velocity within the boundary layer «r = (TJPJ" 1 u' = local turbulent velocity scale w bl = boundary-layer mass flux below y where u/u e = 0.99 bieed = bleed rate XId -streamwise spacing of bleed holes Y/d = cross stream spacing of bleed holes y = distance normal to the wall y + = yu r lv w a = bleed hole angle to surface 8 = boundary-layer thickness \ju t = turbulent viscosity v w = kinematic viscosity at the wall p -density p w = density at the wall T W = wall shear stress

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