A body in nonlinear near-wall shear flow: numerical results for a flat plate

Abstract

Abstract Direct numerical solutions are described for flow past a body placed in an otherwise uniform shear layer adjoining a wall. The study is associated with potential impact of the body onto the wall. Steady two-dimensional flow solutions are calculated for an inclined flat plate in particular, covering cases of zero wall velocity, positive wall velocity and negative wall velocity, with the plate being at varying orientations and distances from the wall. Substantial flow separation is found with reduced proximity to the wall or increased plate incidence, caused partly by the cutting off of the mass flux in the gap between the body and the wall as impact is neared. Other distinct flow characteristics that emerge with increased local Reynolds number are the extent of the enhanced wake responses, greatly condensed upstream influence near the leading edge, increased sensitivity to body orientation, the pressure dominance in the total lift and moment on the body, new insight into the complex flow structure and quantitative agreement with a recent viscous–inviscid interaction analysis on scales.