Multi-Objective Evolutionary Optimisation of Submarine Propulsion Design
Author: Skinner, Benjamin A.
Supervisor: Palmer, Partic; Parks, Geoffrey
Institution: St Catharine’s College, University of Cambridge
At present, the future of submarine propulsion is in contention, with opinion split over the most suitable propulsive platform to adopt for the propulsion of future nuclear powered submarines. This thesis presents an optimisation framework that employs simulation-based design optimisation to aid the design engineer with the selection of the most suitable propulsion system. By employing simulation techniques such as inverse multi-fidelity simulation, and optimisation techniques such as hybrid multi-objective evolutionary optimisation, an optimisation framework has been developed that facilitates the comparison of a range of different propulsion system concepts. Such concepts include direct all-electric drive, geared multiple electric motor all-electric drive, hybrid mechanical-electric drive, and conventional mechanical drive. Information regarding trade-offs in design are assessed, including trade-offs between device efficiencies, trade-offs between different propulsion system concepts, and trade-offs in propulsive efficiency with submarine speed. Detailed optimal design specifications of the most efficient propulsion system concept are also established, including the optimal design’s robustness to changes in submarine speed. This information generated by the optimisation framework enables the design engineer to make a more informed decision on the most appropriate system to adopt for future submarine propulsion, thus facilitating the generation of more effective propulsion system designs. The utility of the optimisation framework culminates in the generation of a hybrid drive propulsion system design that offers potential savings in energy consumption of ~30% over current submarine propulsion systems.