Scaling law of resolved-scale isotropic turbulence and its application in large-eddy simulation

Abstract

Eddy-damping quasinormal Markovian (EDQNM) theory is employed to calculate the resolved-scale spectrum and transfer spectrum, based on which we investigate the resolved-scale scaling law. Results show that the scaling law of the resolved-scale turbulence, which is affected by several factors, is far from that of the full-scale turbulence and should be corrected. These results are then applied to an existing subgrid model to improve its performance. A series of simulations are performed to verify the necessity of a fixed scaling law in the subgrid modeling.

Spectral non-equilibrium property in homogeneous isotropic turbulence and its implication in subgrid-scale modeling

“…However, as already discussed in Refs. [33] and [38], this difference is not evident and could be appropriately neglected in LES applications. Two groups of LES test cases under 64 3 resolution, with each containing six cases, are performed for validate the performance of this improved Smagorinsky model.…”

“…If we carefully visit the regions of coherent structures, it can be found that none of these assumptions is satisfied: i) the Reynolds number may be not high (usually Re λ < 1000), which does not lead to obvious inertial range [27]; ii) the flow is usually inhomogeneous; iii) the local isotropy is not usually satisfied even in small scales; iv) the flow is in non-equilibrium. Existing studies have focused on and (partly) solved the first three problems [27][28][29][30][31][32][33][34], however, there is still few attempts on the fourth problem, i.e., the non-equilibrium fact, in the domain of SGS modeling [35,7]. In this case, in the following we would like to introduce our previous attempt of considering the non-equilibrium in a simplest situation, i.e., the homogeneous isotropic turbulence (HIT).…”

A criterion of orthogonality on the assumption and restrictions in subgrid-scale modelling of turbulence

“…This fact has been discussed in Refs. [3,13,15], but we did not manage to give a convincing theoretical explanation. In Ref.…”

“…There are various types of restrictions, for example the inviscid simplification [10], the scaling laws [15,22,23], the filter similarity [24], the velocity profile restriction [25], etc.. We remark that there can be multiple restrictions in one SGS model, for example in Ref. [10] four restrictions are employed: the inviscid simplification, the scaling law, the stationary simplification of structure function, and the subgrid feasibility for Taylor expansion.…”

A Closure for Isotropic Turbulence Based on Extended Scale Similarity Theory in Physical Space

“…Neglecting the time-dependent term, as is proved by DNS in Ref. [8], the classical Kolmogorov equation can be simply written as [9−12] 𝐷 111 = 6𝜈𝐷 ′ 11 −…”