CFD-Based Multiobjective Stochastic Optimization of a Waterjet Propelled High Speed Ship.

The present paper is complementary to the work by Dietz et al. (2012) and Peri et al. (2012), with more focus on the development and validation of a CFD-based multiobjective stochastic optimization method. The numerical optimization method is applied for the initial design of a waterjet propelled high-speed ship. The scheme investigated in the present study is based on Evolutionary Algorithm (EA), a more suitable scheme for multiobjective optimization than other alternatives. Another important feature of EA is upward scalability in parallel computing by introducing the recent advancement of Information Technology, which actually realizes a high-performance optimization framework in the present study. In addition, the concepts of Variable Fidelity/Physics and hierarchical optimization approach are adopted, so as to increase the efficiency of the whole optimization problem by using two different levels of accuracy. That is, both Unsteady RANS and Potential Flow based CFD methods together with Asynchronous Evaluator model for interface with optimization module are used in the present study. A practical geometry modelling method to yield new designs is used as successfully demonstrated in the previous work. In the following, an overview of the present method is given, and results are presented and discussed for Delft Catamaran test cases. The results appear very promising, which support overall validity and effectiveness of the optimization framework developed in the present study.