Adjoint-based variational optimal mixed models for large-eddy simulation of turbulence

Yuan，Zelong1,2; Wang，Yunpeng1,2; Wang，Xiaoning1,2; Wang，Jianchun1,2

2023-07-01

10.1063/5.0155184

Physics of Fluids   Impact Factor & Quartile

1070-6631

1089-7666

An adjoint-based variational optimal mixed model (VOMM) is proposed for subgrid-scale (SGS) closure in large-eddy simulation (LES) of turbulence. The stabilized adjoint LES equations are formulated by introducing a minimal regularization to address the numerical instabilities of the long-term gradient evaluations in chaotic turbulent flows. The VOMM model parameters are optimized by minimizing the discrepancy of energy dissipation spectra between LES calculations and a priori knowledge of direct numerical simulation using the gradient-based optimization. The a posteriori performance of the VOMM model is comprehensively examined in LES of three turbulent flows, including the forced homogeneous isotropic turbulence, decaying homogenous isotropic turbulence, and temporally evolving turbulent mixing layer. The VOMM model outperforms the dynamic Smagorinsky model, dynamic mixed model (DMM), and approximate deconvolution model in predictions of various turbulence statistics, including the velocity spectrum, structure functions, statistics of velocity increments and vorticity, temporal evolutions of the turbulent kinetic energy, dissipation rate, momentum thickness and Reynolds stress, as well as the instantaneous vortex structures at different grid resolutions and times. In addition, the VOMM model only takes up 30% time of the DMM model for all flow scenarios. These results demonstrate that the proposed VOMM model improves the numerical stability of LES and has high a posteriori accuracy and computational efficiency by incorporating the a priori information of turbulence statistics, highlighting that the VOMM model has a great potential to develop advanced SGS models in the LES of turbulence.

SCI

English

First ; Corresponding

National Natural Science Foundation of China (NSFC)["91952104","92052301","12172161","91752201"] ; NSFC Basic Science Center Program[11988102] ; Shenzhen Science and Technology Program[KQTD20180411143441009] ; Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0103] ; Department of Science and Technology of Guangdong Province[2020B1212030001]

Mechanics ; Physics

Mechanics ; Physics, Fluids & Plasmas

WOS:001025235200015

AIP Publishing

PHYSICS

2-s2.0-85164282781

Scopus

1.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.Guangdong-Hong Kong-Macao Joint Laboratory for Data-Driven Fluid Mechanics and Engineering Applications,Southern University of Science and Technology,Shenzhen,518055,China

Yuan，Zelong,Wang，Yunpeng,Wang，Xiaoning,et al. Adjoint-based variational optimal mixed models for large-eddy simulation of turbulence[J]. Physics of Fluids,2023,35(7).

Yuan，Zelong,Wang，Yunpeng,Wang，Xiaoning,&Wang，Jianchun.(2023).Adjoint-based variational optimal mixed models for large-eddy simulation of turbulence.Physics of Fluids,35(7).

Yuan，Zelong,et al."Adjoint-based variational optimal mixed models for large-eddy simulation of turbulence".Physics of Fluids 35.7(2023).