Interfacial waves produced by a submerged body moving in a layered fluid

Download

PDF - Publishers print Download (8Mb)

Description/Abstract

Velocity potential solutions are derived for an arbitrary shaped body moving horizontally in a fluid system consisting of three layers, the lower layer of infinite depth. The body may be located in any one of the three layers. The boundary conditions on the free surface and interface are linearised and a radiation condition imposed. Expressions for the far field free surface and interface elevations are derived. A three dimensional extension of Lagally's theory provides a method which allows the wave resistance of the body to be determined. The application of a slender body approximation permits the derivation of analytical expressions for the elevations and wave resistance. Plots of the far field free surface and interface wave systems are presented when the body is located in each layer. The wave resistance of a prolate spheroid length L to diameter d for a series of L/d ratios is calculated over a Froude number range. The "dead water" effect being apparent in every case. The results of other parametric studies are also included.