Journal article
Stochastic optimization methods for ship resistance and operational efficiency via CFD
Structural and multidisciplinary optimization, Vol.57(2), pp.735-758
08/14/2017
DOI: 10.1007/s00158-017-1775-4
Abstract
Hull-form stochastic optimization methods are presented and evaluated for resistance reduction and operational efficiency (operability), addressing stochastic sea state and operations. The cost/benefit analysis of the optimization procedure is presented by comparison of four hierarchical problems, from stochastic most general to deterministic least general. The parent hull is a high-speed catamaran, with geometrical constraints for maximum variation of length, beam, draft, and displacement. Problem 1 is used as a benchmark for the evaluation of the other problem formulations and is defined as a multi-objective stochastic optimization for resistance and operability, considering stochastic sea state and speed, but limited to head waves. Problem 2 is a multi-objective stochastic optimization for resistance and motions at fixed sea state and speed. Problem 3 is a multi-objective deterministic optimization for resistance and motions using a single regular wave at fixed speed. Problem 4 is a single-objective deterministic optimization for calm-water resistance at fixed speed. The design optimization is based on hull-form modifications by the Karhunen-Loève expansion of a free-form deformation, URANS-based CFD simulations, regular wave approximations for irregular waves, metamodels and multi-objective particle swarm. The design optimization achieves an 8.7, 23, 53, and 10% average improvements for problems 1, 2, 3, and 4, respectively. Comparing to problem 1, problem 2, 3, 4 optimized designs have average performances 1, 2.1 and 1.7% worse, respectively. The most efficient problem, from the computational cost/benefit viewpoint, is problem 3. Nevertheless, problem 1 is needed to evaluate and compare the stochastic performance of the designs and finally assess the optimization cost/benefit.
Details
- Title: Subtitle
- Stochastic optimization methods for ship resistance and operational efficiency via CFD
- Creators
- Matteo Diez - University of IowaEmilio F Campana - National Research CouncilFrederick Stern - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Structural and multidisciplinary optimization, Vol.57(2), pp.735-758
- Publisher
- Springer Berlin Heidelberg
- DOI
- 10.1007/s00158-017-1775-4
- ISSN
- 1615-147X
- eISSN
- 1615-1488
- Grant note
- N00014-14-1-0195 / Office of Naval Research (http://dx.doi.org/10.13039/100000006) N62909-11-1-7011 / Office of Naval Research Global (http://dx.doi.org/10.13039/100007297)
- Language
- English
- Date published
- 08/14/2017
- Academic Unit
- Mechanical Engineering
- Record Identifier
- 9984196528302771
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