Icebreaker Propulsion System Simulation. Phase III. Propulsion System Behavior During Propeller - Ice Interactions.

摘要

This phase of the Icebreaker Propulsion System Simulation reports on the results of studies directed at improving the overall in-ice icebreaker performance through improved propulsion system design. A mathematical description of the ice-torque problem for dynamic and quasi-steady state behavior is presented, and additional propulsion system electrical circuit dynamics necessary to more adequately describe propulsion system dynamic behavior during propeller-ice encounters are described. The predicted performance of the USCGC GLACIER when subjected to the ice load torque model is presented. A load control scheme (designed to extend the constant horsepower range of the propulsion system well below bollard propeller speed) is developed and incorporated into the basic system equations. The performance of a system of the same size as the GLACIER incorporating this load control system and subjected to the same ice loads is also presented. It is concluded that the incorporation of a load control system significantly increases the capability of the icebreaker propulsion system when operating in ice. (Author)