A numerical study of flow separation and reattachment on a blunt plate

A two-dimensional time-dependent numerical study of separating and reattaching flow over a blunt plate is described. Four Reynolds numbers, Re = 150, 250, 300, and 1000, are studied. The first three are in the steady flow regime and calculated values of reattachment lengths compare well with experimental data. For Re = 1000, the separated shear layer becomes unsteady with the formation of spanwise vortices. These vortices coalesce and are shed periodically from the reattachment region. Although the resulting flow field is known to be three dimensional, the current two-dimensional calculation is able to predict important flow properties. Calculated time-dependent properties such as vortex shedding frequency and convection velocities compare well with experimental data. The present study is a precursor to a three-dimensional simulation.