Stability analysis of a circularly towed cable-body system

This paper investigates the dynamic response of a circularly towed cable-body system with fluid drag loading. The system model includes non-linear steady state equations and linear vibrational equations about steady state. The steady state equations are solved numerically via a shooting technique. The vibrational equations are linearized and discretized using Galerkin's method. Numerical results show the existence of multiple steady state solutions for small fluid drag, large end mass, or high rotation speed. Divergently unstable solutions lead to jump phenomena. High rotation speed causes Hopf bifurcations and second mode flutter for small point mass radius or third mode flutter for large point mass radius. Generally, increasing drag increases the stable regions. Stable single-valued solutions always exist for sufficiently low rotation speed.