Publication

Low-Dissipation Simulation Methods and Models for Turbulent Subsonic Flow

Rozema, W., Verstappen, R. W. C. P., Veldman, A. E. P. & Kok, J. C., Jan-2020, In : Archives of Computational Methods in Engineering. 27, 1, p. 299-330 32 p.

Research output: Contribution to journalArticleAcademicpeer-review

The simulation of turbulent flows by means of computational fluid dynamics (CFD) is highly challenging. The costs of an accurate direct numerical simulation (DNS) are usually too high, and engineers typically resort to cheaper coarse-grained models of the flow, such as large-eddy simulation (LES).

To be suitable for the computation of turbulence, methods should not numerically dissipate the turbulent flow structures. Therefore, energy-con\-ser\-ving discretizations are investigated, which do not dissipate energy and are inherently stable because the discrete convective terms cannot spuriously generate kinetic energy. They have been known for incompressible flow, but the development of such methods for compressible flow is more recent. This paper will focus on the latter: LES and DNS for turbulent subsonic flow.

A new theoretical framework for the analysis of energy conservation in compressible flow is proposed, in a mathematical notation of square-root variables, inner products, and differential operator symmetries. As a result, the discrete equations exactly conserve not only the primary variables (mass, momentum and energy), but also the convective terms preserve (secondary) discrete kinetic and internal energy. Numerical experiments confirm that simulations are stable without the addition of artificial dissipation.

Next, minimum-dissipation eddy-viscosity models are reviewed, which try to minimize the dissipation needed for preventing sub-grid scales from polluting the numerical solution. A new model suitable for anisotropic grids is proposed: the anisotropic minimum-dissipation (AMD) model. This model appropriately switches off for laminar and transitional flow, and is consistent with the exact sub-filter tensor on anisotropic grids.

The methods and models are first assessed on several academic test cases: channel flow, homogeneous decaying turbulence and the temporal mixing layer.
As a practical application, accurate simulations of the transitional flow over a delta wing have been performed.
Original languageEnglish
Pages (from-to)299-330
Number of pages32
JournalArchives of Computational Methods in Engineering
Volume27
Issue number1
Early online date20-Dec-2018
Publication statusPublished - Jan-2020

    Keywords

  • compressible flow, turbulent flow, large-eddy simulation, discrete conservation, skew-symmetric discretization

View graph of relations

ID: 76196452