On the water impact of general two-dimensional sections

We consider the analytic solution of the impact problem of a general two-di mensional body entering initially calm water. Of interest are the water spl ash-up height, the force history and the pressure distribution on the body. The potential-flow formulation of Wagner (Wagner, H. Math. Mech. 1932;12(4 ):193-215) is applied and extended to an arbitrary body section with the bo dy boundary condition imposed on the exact wetted surface of the body. For wedges and circular cylinders, we derive closed-form solutions using confor mal mapping for the boundary-value problem at any instant. These solutions reduce to those of Wagner in the small deadrise angle/shallow-body limit an d are verified for the general case by the existing experiments and fully n onlinear numerical simulations. For ship-like sections, we develop a genera l scheme based on Lewis-form representations for which we also obtain analy tic solutions. For illustration, the solution for a bow flare section is ob tained which compares favorably with experiments. The present approach gene ralizes Wagner's method to a wide class of body sections and is of immediat e practical use in the study of ship slamming. (C) 1999 Elsevier Science Lt d. All rights reserved.