Stern slamming of a chemical tanker in irregular head waves

Abstract

Slamming loads on the stern of a chemical tanker are predicted by using an Arbitrary Lagrangian Eulerian (ALE) algorithm implemented in LS-DYNA and a Modified Longvinovich Model (MLM) which is derived from the potential velocity theory and Wagner's condition. Ship motions in irregular sea states are calculated numerically by a fully nonlinear time domain method based on the strip theory, and then the calculated relative vertical velocity between the ship section on the stern and wave surface is applied in the Arbitrary Lagrangian Eulerian algorithm for slamming load calculation. The problem is solved by simulating water entry of 2D ship sections of the ship model at a constant speed. Model tests of the chemical tanker in irregular seas are conducted to obtain the ship motions and wave-induced loads. The numerical slamming loads are compared with the measured ones and the analytical calculations from the Modified Longvinovich Model.