Separation in slightly viscous flow

We present a scenario for separation in slightly viscous incompressible turbu-lent flow around a solid body supported by computation, mathematical analysis and experimental observation, which is fundamentally different from the scenario for viscous laminar flow by Prandtl based on adverse pressure gradients retarding the flow to stagnation at separation. We make a distinction betweeen separation from a laminar boundary layer with no-slip boundary condition and a turbulent boundary layer with slip. We note that separation occurs if @