Most of the problems in the maritime world involve objects (ships, submarines, offshore platforms, renewable energy systems) which move freely due to the hydro and aerodynamic loads they are subject, and their structural properties. While solving the fluid (Navier-Stokes) equations permit to compute these loads, solving the structural equations (or equations-of-motion or rigid-body dynamic equations) permit to calculate the resulting motions. The coupling of these two sets of equations is therefore important to be taken into account, in order to fully characterize the dynamics of these objects. In ReFRESCO that is possible.
The movies below present the results of 3DoF coupled simulations of a free-moving semi-submersible platform at Reynolds of the order of 1E5. The top one illustrates a sway decay numerical test; the bottom one a VIM (Vortex-Induced-Motion) numerical calculation with the platform at 45deg of heading with respect to the incoming flow.