Loading due to interaction of waves with colinear and oblique currents

Abstract

A study on the loading of an oblique surface wave and a surface current field on a fixed vertical slender cylinder in a 3D flow frame is illustrated in the present paper. The three dimensional expressions describing the characteristics of the combined wave–current field in terms of mass, momentum and energy flux conservation equations are formulated. The parameters before the interaction of the oblique wave-free uniform current and current-free wave are used to formulate the kinematics of the flow field. These expressions are also employed to formulate and calculate the loads imparted by the wave–current combined flow on a bottom mounted slender vertical cylinder. In the present study two different situations are assumed where current is uniform over depth and also acting over a layer of fluid that extends from the free surface to a specified finite depth. In this paper we extend the approach considered in Zaman and Baddour (2004) for the wave–current analysis. Morison et al. (1950) equation is deployed for the load computations in all cases. The above models are utilized to compute the loads and moments on a slender cylinder for a wave with varying range of incidence current field.