Numerical simulations of water flow around ocean mining piping

Ocean mining systems that incorporate a single or double lift pipe are two methods used to obtain polimetallic nodules from the seabed. The pipe must be equipped with main cables and flexible pipe attached to the mining vehicle collecting nodules. While mining, the pipes in the vertical configuration are moving along with the ship above. They are subjected to currents in the water column. Such current-induced hydrodynamic drag results in a vertical deflection, which is dependent – among other factors such as varying current velocity at points along the length of the pipe. The present paper presents results of computer simulations using commercial CFD software to model the hydrodynamic forces acting on the vertical pipe of ocean mining systems. The results present the influence of the water flow direction in relation to the lift pipe on the hydrodynamic force and torsional moment acting upon the pipe.