A regularized deconvolution method for turbulent closure modeling in implicitly filtered large-eddy simulation

This report presents a novel continuous deconvolution method which is used to solve the closure problem in Large Eddy Simulation (LES for short) leading to a new LES model. In the deconvolution method described herein the flow velocities u are approximated by their average ũ on a fine intermediate length scale γ and then, by means of an exact extrapolation formula, expressed in terms of the averaged flow ū on the length scale α, which we seek to resolve. We prove existence, uniqueness and regularity of the weak solution w(α, γ) of the resulting LES models as well as energy estimates of the weak solution that are uniform in the intermediate length scale γ of the deconvolution procedure. We show also that the modeling error ‖ū - w(α, γ)‖ is driven only by the deconvolution error ‖u - ũ‖ and is independent of the resolved scale α.

Download Full-text

Modeling of sub-grid dispersion in large-eddy simulation using regularized deconvolution method

2018 AIAA Aerospace Sciences Meeting ◽

10.2514/6.2018-2082 ◽

2018 ◽

Author(s):

Qing Wang ◽

Xinyu Zhao ◽

Matthias Ihme

Keyword(s):

Large Eddy Simulation ◽

Deconvolution Method ◽

Eddy Simulation ◽

Large Eddy ◽

Grid Dispersion

Download Full-text

Noll’s Axioms and Formulation of the Closure Relations for the Subgrid Turbulent Tensor in Large Eddy Simulation

WSEAS TRANSACTIONS ON FLUID MECHANICS ◽

10.37394/232013.2020.15.8 ◽

2020 ◽

Vol 15 ◽

Keyword(s):

Kinetic Energy ◽

Large Eddy Simulation ◽

Turbulent Stress ◽

Frame Indifference ◽

Eddy Simulation ◽

Material Frame Indifference ◽

Large Eddy ◽

Turbulent Closure ◽

Closure Relations ◽

Material Frame

In this paper, the relation between the Noll formulation of the principle of material frame indifference and the principle of turbulent frame indifference in large eddy simulation, is revised. The principle of material frame indifference and the principle of turbulent frame indifference proposed by Hutter and Joenk imposes that both constitutive equations and turbulent closure relations must respect both the requirement of form invariance, and the requirement of frame independence. In this paper, a new rule for the formalization of turbulent closure relations, is proposed. The generalized SGS turbulent stress tensor is related exclusively to the generalized SGS turbulent kinetic energy, which is calculated by means of its balance equation, and the modified Leonard tensor.

Download Full-text