A High-Order Variational Multiscale Approach to Turbulence for Compact Nodal Schemes

TL;DR

This paper introduces a high-order variational multiscale method tailored for compact nodal schemes in turbulence modeling, enhancing accuracy and robustness in large-eddy simulations of compressible flows.

Contribution

It extends variational multiscale modeling to high-order flux reconstruction schemes, providing a rigorous mathematical framework and demonstrating improved turbulence simulation results.

Findings

Improved agreement with filtered DNS data on coarse grids.

Highlighting the importance of de-aliasing and upwinding in LES accuracy.

Demonstrated effectiveness on Taylor-Green vortex benchmark.

Abstract

This article presents a formulation that extends the variational multiscale modelling for compressible large-eddy simulation to a vast family of compact nodal numerical methods represented by the high-order flux reconstruction scheme. The theoretical aspects of the proposed formulation are laid down via rigorous mathematical derivations which clearly expose the underlying assumptions and approximations and provide sufficient details for accurate reproduction of the methodology. The final form is assessed on a Taylor-Green vortex benchmark with Reynolds number of 5000 and compared to filtered direct numerical simulation data. These numerical experiments exhibit the important role of sufficient de-aliasing, appropriate amount of upwinding from Roe's numerical flux and large/small scale partition, in achieving better agreement with reference data, especially on coarse grids, when compared to the baseline implicit large-eddy simulation.