Design-order, non-conformal low-Mach fluid algorithms using a hybrid CVFEM/DG approach

JOURNAL OF COMPUTATIONAL PHYSICS

卷:359

Article

Domino, Stefan P.¹ 

[1] Sandia Natl Labs Computat Thermal & Fluid Mech, 1541 POB 5800 MS 0828, Albuquerque, NM 87109 USA

关键词: Control volume finite element;    Discontinuous Galerkin;    Higher-order;    Sliding mesh;    Non-conformal;   

DOI  :  10.1016/j.jcp.2018.01.007

来源: Elsevier

【 摘 要 】

A hybrid, design-order sliding mesh algorithm, which uses a control volume finite element method (CVFEM), in conjunctionwith a discontinuous Galerkin (DG) approach at nonconformal interfaces, is outlined in the context of a low-Mach fluid dynamics equation set. This novel hybrid DG approach is also demonstrated to be compatible with a classic edgebased vertex centered (EBVC) scheme. For the CVFEM, element polynomial, P, promotion is used to extend the low-order P = 1CVFEM method to higher-order, i.e., P = 2. An equalorder low-Mach pressure-stabilized methodology, with emphasis on the non-conformal interface boundary condition, is presented. A fully implicitmatrix solver approach that accounts for the full stencil connectivity across the non-conformal interface is employed. Acomplete suite of formal verification studies using the method of manufactured solutions (MMS) is performed to verify the order of accuracy of the underlying methodology. The chosen suite of analytical verification cases range from a simple steady diffusion system to a traveling viscous vortex acrossmixed-order non-conformal interfaces. Results from all verification studies demonstrate either second-or third-order spatial accuracy and, for transient solutions, second-order temporal accuracy. Significant accuracy gains in manufactured solution error norms are noted even with modest promotion of the underlying polynomial order. The paper also demonstrates the CVFEM/DG methodology on two production-like simulation cases that include an inner block subjected to solid rotation, i.e., each of the simulations include a sliding mesh, non-conformal interface. The first production case presented is a turbulent flow past a high-rate-of-rotation cube (Re, 4000; RPM, 3600) on like and mixed-order polynomial interfaces. The final simulation case is a full-scale Vestas V27 225 kW wind turbine (tower and nacelle omitted) in which a hybrid topology, low-order mesh is used. Both production simulations provide confidence in the underlying capability and demonstrate the viability of this hybrid method for deployment towards high-fidelity wind energy validation and analysis. (C) 2018 Elsevier Inc. All rights reserved.

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