The effects of interference and viscosity in the Kelvin ship-wave problem

Abstract

A comparison is made between the effects of spreading the source (thus causing interference) and of viscosity in the Kelvin ship-wave problem. Two simple pressure distributions are considered and in both it is found that spreading, like viscosity, introduces a multiplicative damping factor into the inviscid pressure-point solution. In one case it is this factor, rather than that of viscosity, which dominates the decay of the wave profile, while, in the other, the effects alternate in importance as one travels along any particular wave crest.