Chesapeake Section Of SNAME Hears Paper On Dynamic Analysis Of COGAS Propulsion Plant
The Chesapeake Section of The Society of Naval Architects and Marine Engineers held its third meeting of the 1976-77 season at the Officers Club at the Walter Reed Army Hospital. The subject of the meeting was the "Dynamic Analysis of a COGAS Propulsion Plant." Presentation of the paper followed a social hour and dinner.
The authors were: J.W. Abbott, head of Systems Engineering and Analysis Branch, NAVSEC; J.G. Mclntire, control systems engineer, NAVSEC, and C.J. Rubis, president of Propulsion Dynamics, Incorporated. Their paper was entitled "A Dynamic Analysis of a COGAS Propulsion Plant." It described a dynamic and control simulation of a 30,000-hp combined gas and steam (COGAS) propulsion plant powering a single- screw controllable-pitch propeller on a frigate-type ship. The propulsion plant consisted of one General Electric LM 2500 gas turbine engine with a waste-heat recovery boiler driving a steam turbine to augment gas-turbine propulsion power. The all digital simulation included equations and algorithms of the ship, propeller, and control system and dynamic models of the gas turbine and steam system. Results of computer simulations which investigated the performance of various COGAS plant control system deterials signs were presented. These simulations included acceleration from various forward speeds, crashback from full ahead, and crash ahead from full astern. Results were described in terms of peak thrust and torque transmission loads, plus ship maneuverability characteristics as compared to a simple cycle gas-turbine plant. At the conclusion of the presentation, a lively discussion period took place.