Added Mass For Bodies Moving Arbitrarily In Fluid With Free Surface

It is rather hard for the added mass of nonlinear flow with free surface to be developedfrom the traditional derivation and conclusion. In this paper, a deriving process for addedmass is presented, which is different from the traditional one, and they lead to the same resultas computing the added mass in infinite domain. The new method is also employed to thenonlinear flow with free surface in this paper, which provides a method and conclusion forarbitrary motion of bodies.In the new method, added mass of both a square column in different depth and thecolumn with part out of the free surface is simulated. The results of a column in deep watershow an excellent agreement with the results in infinite domain, that obtained by Isaacson andNewman. As the square approaches to the free surface and cross over it, the added mass tendsto a constant. The result is thorough different from the result by treating the free surface aswall. The conclusion in this paper can be considered as direct generalization of the traditionalconclusion of added mass in infinite domain.