Unsteady development of the boundary layer in the vicinity of a rear stagnation point

Indications of a singularity associated with unsteady separation are reviewed within the framework of semi-similar solutions to the unsteady boundary layer equations. It is shown that when the boundary layer equations are formulated in semi-similar form there is an indication that a singularity exists in the solutions to these equations. In cases where the singularity occurs and separation is expected, it occurs at or near a point which has all the features of separation postulated in the Moore-Rott-Sears model.