Gilkeson, CA, Toropov, VV, Thompson, HM et al. (3 more authors) (2014) Dealing with numerical noise in CFD-based design optimization. Computers and Fluids, 94. 84 - 97. ISSN 0045-7930
Abstract
Numerical noise is an inevitable by-product of Computational Fluid Dynamics (CFD) simulations which can lead to challenges in finding optimum designs. This article draws attention to the issue, illustrating the difficulties it can cause for road vehicle aerodynamics simulations. Firstly a benchmark problem is used to assess a range of turbulence models and grid types. Large noise amplitudes up to 22% are evident for solutions computed on unstructured tetrahedral grids whereas computations on hexahedral and polyhedral grid structures exhibit substantially less noise. The Spalart Allmaras turbulence model is shown to be far less susceptible to noise levels than two other commonly-used models for this application. Secondly, multi-objective aerodynamic shape optimization is applied to a fairing for a practical road vehicle which is parameterised in terms of three design variables. Moving Least Squares (MLS) metamodels are constructed from 50 high-fidelity CFD solutions for two objective functions. Subsequent optimization is successful for the first objective, however numerical noise levels in excess of 7% give rise to difficulties for the second one. A revision to the problem leads to success and the construction of a small Pareto Front. Further analysis underlines the inherent capability of MLS metamodels in dealing with noisy CFD responses.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, Elsevier. This is an author produced version of a paper published in Computers and Fluids. Uploaded in accordance with the publisher's self-archiving policy. NOTICE: this is the author’s version of a work that was accepted for publication in Computers and Fluids. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Computers and Fluids, 94,(2014) DOI 10.1016/j.compfluid.2014.02.004 |
Keywords: | Numerical noise; Optimization; Moving least squares; Metamodel; CFD; Aerodynamics |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 11 Jun 2014 10:57 |
Last Modified: | 15 Jan 2018 21:19 |
Published Version: | http://dx.doi.org/10.1016/j.compfluid.2014.02.004 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.compfluid.2014.02.004 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:79155 |