Abstract: This paper presented a 4-DOF semi-dynamic mathematical model for the dynamics of underwater faired cable, which is used to study the macroscopical dynamics through numerical simulation method. To model the faired cable’s dynamics suitably, its motions were analyzed and resolved into 3-DOF dynamic translational motions and 1-DOF steady state rotary motion about cable axis according to its kinematic characters, then the governing equations were developed based on the above and the principle of lumped parameter method. This model can account for cable weight, buoyancy, hydrodynamic forces as well as torsional moments, which is numerically solved by 4th order Runge-Kutta integration method. Some numerical examples were given to study its dynamics, and some useful conclusions were drawn.  

Key words: underwater faired cable, towed system, lumped parameter method, numerical simulation