Abstract: Aimed at the underwater multi-cable multi-body towed system, a mathematical model and the corresponding numerical solution are proposed to predict and analyze its dynamic characteristics in various conditions. The model consists of three parts: the governing equation of cables is given based on the lumped mass method; the underwater towed body, as a key part of the system, is accurately described by the 6 degree-of-freedom governing equations for submarines; the other tiny towed body in the system is simplified as a mass point and is incorporated into the cable node governing equation because of its small dimension. Coupling boundary conditions for towed cable and body are given to unite the three parts together, which is numerically solved by using the 4th order Runge-Kutta integration method. Finally, numerical simulations for a four-cable and two-body towed system are conducted to study its dynamic response in various conditions, and some conclusions are drawn from the results.

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