Implementing a low-dissipative symmetry preserving scheme in OpenFOAM

Hopman, Jannes (2020) Implementing a low-dissipative symmetry preserving scheme in OpenFOAM. Master's Thesis / Essay, Applied Physics.

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Abstract

In this work, the fully-conservative symmetry preserving discretization method ofVerstappen and Veldman (2003), which was later generalized to unstructured collo-cated grids by Trias et al. (2014), is implemented in open source CFD software Open-FOAM. By upholding underlying symmetries in operators of the Navier-Stokes equa-tions, a discretization scheme is derived that preserves energy at all length scales toreduce numerical dissipation, and more accurately depicts turbulence. Using a Taylor-Green vortex case, significant improvements in terms of numerical dissipation wereshown in comparison with OpenFOAM’s standard icoFoam solver. This effect was mainlycaused by the Van Kan pressure prediction method , in comparison to the Chorinmethod [4], which does not include a pressure prediction. The spatial discretizationof the symmetry preserving method, which uses midpoint interpolation and projecteddistances in its gradients, simultaneously improved stability, even on distorted grids,while slightly under-estimating physical diffusion. By performing a temporal consis-tency study on the lid-driven cavity flow, it was shown that the pressure predictionmethod was able to increase the order of accuracy of the pressure error fromO(∆t∆h2)toO(∆t2∆h2). Nevertheless, in a more realistic turbulent channel fow case, the low-dissipative character of the symmetry preserving method started to show some instabil-ities

Item Type:	Thesis (Master's Thesis / Essay)
Supervisor name:	Verstappen, R.W.C.P. and Onck, P.R.
Degree programme:	Applied Physics
Thesis type:	Master's Thesis / Essay
Language:	English
Date Deposited:	14 May 2020 08:50
Last Modified:	14 May 2020 08:50
URI:	https://fse.studenttheses.ub.rug.nl/id/eprint/21903

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