Steady wave drift force on basic objects of symmetry

Abstract

The steady wave drift force on a submerged body is a second-order quantity. With a potential flow assumption, the force arises from the diffraction and radiation of the waves from the interaction with the body. For a fixed body in waves the steady force is contributed from the wave diffraction effect alone. Numerical solutions are generally needed for the computation of the steady drift force on submerged structures. In this paper the steady wave drift forces on several fixed bodies of basic shapes are derived in closed form. The paper addresses the steady drift forces on the following basic structures: a vertical circular cylinder, a submerged horizontal cylinder, a bottom-seated horizontal half cylinder, and a bottom-seated hemisphere. The results developed demonstrate the importance of various independent non-dimensional parameters. A numerical program based on linear diffraction/radiation theory is used to validate the closed form solution.