MODELS FOR NONLINEAR WATER WAVES ON SHEAR CURRENTS.

In offshore design, currents must be included in the wave force design procedure as they always are present due to the actions of the wind, tidal forces, and oceanic circulation. Two wave models are provided for the computer generation of a design (symmetric) wave of given height, H, wave period, T, in a known water depth, h, which propagates on an ambient current which has a velocity profile over depth describable by two or three straight lines. These are the linear and the bilinear shear current models, respectively. These models represent an extension of the Stream Function wave theory described by Dean, which generates a wave propagating on a current with a velocity profile which is constant in magnitude over the depth of the water. These extended models, which include more realistically the shape of the current profile, offer the design engineer a better capability to input accurate current data into the design procedures.