Boundary layer development on a wedge impulsively set into motion

The problem of impulsively-set-into-motion wedge-type (Falkner-Skan) flows is formulated in a new set of scaled coordinates. The boundary layer development occurring in two stages is described. The solution for the impulsively started flat plate is obtained and compared with existing solutions to this special case in order to verify the method of solution. Flows involving an adverse pressure gradient are considered in detail to determine the information that can be gained from the present solution regarding downstream-moving unsteady boundary layer separation. Cases where separation does not occur are identified. It is shown that if separation occurs in the later phase of flow development, it must move with a velocity lower than the local speed at the edge of the boundary layer.