A comparative study of explicit and implicit Large Eddy Simulations using a high-order discontinuous Galerkin solver: application to a Formula 1 front wing

TL;DR

This study compares explicit and implicit Large Eddy Simulation methods using a high-order discontinuous Galerkin solver on a Formula 1 front wing, highlighting their respective strengths and potential for complex aerodynamic simulations.

Contribution

It introduces a comparative analysis of explicit and implicit LES approaches within a high-order DG framework applied to a complex F1 wing model, emphasizing stability and efficiency.

Findings

Implicit LES better captures transition phenomena.

Both LES methods agree with reference data.

Implicit LES allows larger time steps with similar computational cost.

Abstract

This paper explores two Large Eddy Simulation (LES) approaches within the framework of the high-order discontinuous Galerkin solver, Horses3D. The investigation focuses on an Inverted Multi-element Wing in Ground Effect (i.e. 2.5D Imperial Front Wing section) representing a Formula 1 front wing, and compares the strengths and limitations of the two LES methods. The explicit LES formulation relies on the Vreman model, that adapts to laminar, transitional and turbulent regimes. The numerical formulation uses nodal basis functions and Gauss points. The implicit LES formulation, does not require explicit turbulence modeling but relies in the discretization scheme. We use the Kennedy-Gruber entropy stable formulation to enhance stability in under resolved simulations, since we recover the continuous properties such as entropy conservation at a discrete level. This formulation employs Gauss-Lobatto points, which downgrades the accuracy of integration but allows for larger time steps in explicit time integration. We compare our results to Nektar++ [1] showing that both LES techniques provide results that agree well with the reference values. The implicit LES shows to better capture transition and allows for larger time steps at a similar cost per iteration. We conclude that this implicit LES formulation is very attractive for complex simulations.