Hydrodynamics of Ice Mass Near Large Offshore Structure

Abstract

The changes in flow field around an ice mass drifting in a current near a large offshore structure are investigated using potential theory. A formulation in two dimensions is adopted here to allow relatively accurate results to be obtained for very small separation distances, and an approximate method to extend the results to threedimensional applications is described. The motions of the ice mass and current interactions are represented by five unit potentials and the hydrodynamic forces are obtained by the Bernoulli equation. The proximity effects are then generalized by introducing a set of hydrodynamic coefficients for the ice mass, which are expressed in terms of geometry of the structure and ice mass. A numerical model based on the boundary integral method is developed to solve the problem. A set of coefficients for the special case of two circular cylinders is presented in this paper. The strengths and weaknesses of the proposed model, as well as its practical applications, are discussed.