Out of Plane Solutions of Submarines in Free Positive Buoyancy Ascent

摘要

This thesis analyzes the problem of motion stability of submarines in freepositive buoyancy ascent under casualty conditions such as control surface jam and loss of propulsion system response. We employ fully nonlinear, coupled six degree of freedom equations of motion and we allow response to occur in combined vertical and horizontal planes. Continuation and homotopy theory techniques are utilized to trace all possible steady state solutions in six degrees of freedom, while local perturbation reveals their stability properties. Vehicle geometric properties and control surface deflections are used as primary bifurcation parameters. Regions in parameter spaces are identified where extreme sensitivity of solutions to geometric properties and hydrodynamic modeling is present. Submarine stability, Continuation, Bifurcation, Pitchfork, Hysteresis, Cusp.