The equations of motion for the coupled dynamics of a long flexible liferaft and fast rescue cracr in an irregular ocean wave are formulated in two dimensions using the methos of Kane and Levinson (1985). The flexible raft is modeled as spring-connected lumped masses and it is assumed that the motion normal to the wave surface is small and can be neglected, i.e. the bodies move along the propagating wave profile. The wave forces are applied using Morison's equation for bodies in accelerated flow. Wind and loads are similarly modeled using drag coefficients. The equations are solved numerically using the Runge-Kutta routine "ode45" of MATLAB®. The numerical model provides guidelines for predicting the tow loads and motions in severe sea states.
National Research Council of Canada. Institute for Ocean Technology
St. John's, Newfoundland
Technical Report (National Research Council of Canada. Institute for Ocean Technology), no. TR-2008-06 (2008).