Simulation Research On Characteristics Of The COGAG Propulsion System

Combined gas turbine and gas turbine propulsion system(COGAG propulsion system) as an advanced combined power system, adopting several gas turbines as main engine and having high power density, excellent maneuverability and stability, which will be increasingly used as power system in high speed merchant ships and warships. The ship-engine-propeller matching performance will directly affect performance of the system. Therefore, it’s very necessary to have steady-state and dynamic-state study for this propulsion system. Firstly,mathematical models of components of the propulsion system were established. Then, the COGAG propulsion simulation software was developed based on Visual C++ platform. finally,a simulation study of the propulsion system was obtained. The details are as follows:(1) The mathematical models of components of the propulsion system were established.According to the equations of motion of components, the corresponding empirical formula and experimental data, the mathematical models of three-axis turbine, relay -style SSS clutch,gearbox, shaft, controllable-pitch-propeller, rudder and ship resistance were established.(2) The simulation models were established and simulation software were developed.Basing on Visual C++ platform, the overall structure and workflow were established according to the modular and structured idea. The simulation models of components were established based on mathematical models in the second chapter and algorithm models werealso established. Through a combination of the modules and debugging,the complete simulation software of COGAG propulsion system was developed.(3) The steady-state performance study of the propulsion system was obtained. The steady-state matching performance of ship-engine-propeller and the running maps in different propulsion modes were studied. With the target of economic running, the matching performance of ship-engine-propeller was optimized and the most economic running line and the point of maximum speed were determined.(4) The dynamic-state performance study of the propulsion system was obtained. The dynamic-state performance of matching of ship-engine-propeller, operation of combination and splitting, SSS clutch, operationg of turning round and backing up were studied. Change rules of parameters in the process of the movement were obtained and the control strategy and optimization measures were put forward.