A numerical model to simulate launching of evacuation capsules from a ship in beam seas – Simulations and validation using experimental tests

Abstract

A numerical model that simulates the launching of evacuation capsules from a ship in beam seas at F_n=0 has been developed and is presented in this paper. The model includes the motions of the ship and the wave climate in the vicinity of the ship. A boundary integral formulation in the frequency domain is used to calculate the wave climate, which includes radiated and diffracted waves, while the ship motions are determined using a strip-theory approach. The dynamics of the evacuation capsules during launching are simulated in the time domain. Launching can be performed with constant velocity as is the case when launching lifeboats, or with constant acceleration which is used for fall-lifeboats. The motions of the mother ship, the positions and accelerations of the lifeboat or fall-lifeboat are constantly recorded and are validated by comparing the results to experimental model tests. The numerical results are shown to be in good agreement with experimental tests.