  We motivate and discuss several recent results on non-existence of
irrotational inviscid flow around bounded solids that have two or more
protruding corners, complementing classical results for the case of a single
protruding corner. For a class of two-corner bodies including non-horizontal
flat plates, compressible subsonic flows do not exist. Regarding three or more
corners, bounded simple polygons do not admit compressible flows with
arbitrarily small Mach number, and any incompressible flow has unbounded
velocity at at least one corner. Finally, irrotational flow around smooth
protruding corners with non-vanishing velocity at infinity does not exist. This
can be considered vorticity generating by a slip-condition solid in absence of
viscosity.
