Surface waves induced by an impinging jet

The oblique impact of a thin or slender jet on the free surface of a semi-infinite stream is studied. Based on the thickness or radius of the jet the Froude number is assumed to be large and the fluid is assumed to be viscous. By the method of matched asymptotics, the leading term of the solution behind the impact area is constructed. The perturbation solution for the stream away from the impact region and its wake is shown to be equivalent by the linear theory of surface waves with a concentrated load at the impact point and a distributed line load along the wake. These equivalent loads are consistent with considerations of mass and momentum balances and other judicial arguments.