Title:
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Numerical analysis of conservative unstructured discretisations for low Mach flows
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Author:
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Ventosa Molina, Jordi; Chiva Segura, Jorge; Lehmkuhl, Oriol; Muela Castro, Jordi; Pérez Segarra, Carlos David; Oliva Llena, Asensio
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Other authors:
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Universitat Politècnica de Catalunya. Departament de Física; Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics; Universitat Politècnica de Catalunya. CTTC - Centre Tecnològic de la Transferència de Calor |
Abstract:
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This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. https://authorservices.wiley.com/author-resources/Journal-Authors/licensing-and-open-access/open-access/self-archiving.html |
Abstract:
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Unstructured meshes allow easily representing complex geometries and to refine in regions of interest without adding control volumes in unnecessary regions.
However, numerical schemes used on unstructured grids have to be properly defined in order to minimise numerical errors.
An assessment of a low-Mach algorithm for laminar and turbulent flows on unstructured meshes using collocated and staggered formulations is presented. For staggered formulations using cell centred velocity reconstructions the standard first-order method is shown to be inaccurate in low Mach flows on unstructured grids. A recently proposed least squares procedure for incompressible flows is extended to the low Mach regime and shown to significantly improve the behaviour of the algorithm.
Regarding collocated discretisations, the odd-even pressure decoupling is handled through a kinetic energy conserving flux interpolation scheme. This approach is shown to efficiently handle variable-density flows.
Besides, different face interpolations schemes for unstructured meshes are analysed.
A kinetic energy preserving scheme is applied to the momentum equations, namely the Symmetry-Preserving (SP) scheme. Furthermore, a new approach to define the far-neighbouring nodes of the QUICK scheme is presented and analysed. The method is suitable for both structured and unstructured grids, either uniform or not.
The proposed algorithm and the spatial schemes are assessed against a function reconstruction, a differentially heated cavity and a turbulent self-igniting diffusion flame. It is shown that the proposed algorithm accurately represents unsteady variable-density flows. Furthermore, the QUICK schemes shows close to second order behaviour on unstructured meshes and the SP is reliably used in all computations. |
Abstract:
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Peer Reviewed |
Subject(s):
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-Àrees temàtiques de la UPC::Física::Física de fluids -Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids -Fluid dynamics -Low Mach -Segregated algorithm -Unstructured -Collocated -Staggered -Reacting flows -Dinàmica de fluids |
Rights:
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Document type:
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Article - Submitted version Article |
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