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Numerical study of two models for viscous compressible fluid flows

Publikace na Matematicko-fyzikální fakulta |
2021

Tento text není v aktuálním jazyce dostupný. Zobrazuje se verze "en".Abstrakt

Our aim is to evaluate the modelling capability of a recently proposed (Eulerian) model for viscous and heat conducting compressible fluids. The new model differs from the Navier-Stokes in the structure of the diffusive terms.

Most notably, it includes a mass diffusive mechanism. Despite the lack of well-posedness theory, one has to recognize that the standard Navier-Stokes equations are known to give reasonably accurate results for numerous standard problems.

Hence, the new model can not deviate too much from the Navier-Stokes equations for such cases, is it to be an accurate model. The purpose of the paper is to compare the new model with Navier-Stokes and determine an unknown model parameter (alpha) in the new model such that the best matches are obtained.

Using a high-order discontinuous Galerkin scheme, with careful implementations of the boundary conditions, we perform accurate simulations of the two models for a suite of test cases. For the grid converged results, we have, for each problem, compared the two models with respect to a number of measures such as C_L, C_D, C_M, skin friction coefficients, pressure coefficients and Mach number or pressure isolines.

The numerical results reveal a remarkable sameness (the differences are typically 1%) of both models when alpha = 1. (c) 2020 Elsevier Inc. All rights reserved.