Analysis and simulation of a submarine steering control system

the long version

An existing computer simulation of a hydraulic submarine steering control system was analyzed to determine the source of its unrealistic behavior, which included verifying mathematical equations and numerical parameters, duplicating the simulation on another computer, and investigating the validity of the assumptions made in its development. Rudder turning rate and load pressure drop oscillations which were thought to be unrealistic were caused by the neglect of significant rudder moments related to the control surface turning rate. Knowledge of actual system performance was found to be incomplete and further research was suggested. Potentially beneficial modifications in the servovalve and actuator simulators were identified. Continuing work in the field of unsteady rudder behavior was suggested in order to improve simulator and actual system designs.