Ensemble-variational assimilation of statistical data in large-eddy simulation

V Mons, Y Du, TA Zaki - Physical Review Fluids, 2021 - APS
A nonintrusive data assimilation methodology is developed to improve the statistical
predictions of large-eddy simulations (LES). The ensemble-variational (EnVar) approach …

State estimation in turbulent channel flow from limited observations

M Wang, TA Zaki - Journal of Fluid Mechanics, 2021 - cambridge.org
Estimation of the initial state of turbulent channel flow from limited data is investigated using
an adjoint-variational approach. The data are generated from a reference direct numerical …

Linear and nonlinear sensor placement strategies for mean-flow reconstruction via data assimilation

V Mons, O Marquet - Journal of Fluid Mechanics, 2021 - cambridge.org
Reynolds-averaged Navier–Stokes (RANS)-based data assimilation has proven to be
essential in many data-driven approaches, including the augmentation of experimental data …

Assimilation of disparate data for enhanced reconstruction of turbulent mean flows

XL Zhang, H Xiao, GW He, SZ Wang - Computers & Fluids, 2021 - Elsevier
Reconstruction of turbulent flow based on data assimilation methods is of significant
importance for improving the estimation of flow characteristics by incorporating limited …

Unsteady flow enhancement on an airfoil using sliding window weak-constraint four-dimensional variational data assimilation

S Li, C He, Y Liu - Physics of Fluids, 2023 - pubs.aip.org
This study establishes a continuous sliding window weak-constraint four-dimensional
variational approach for reproducing a complete instantaneous flow from sparse …

Rotating shallow water flow under location uncertainty with a structure‐preserving discretization

R Brecht, L Li, W Bauer, E Mémin - Journal of Advances in …, 2021 - Wiley Online Library
We introduce a physically relevant stochastic representation of the rotating shallow water
equations. The derivation relies mainly on a stochastic transport principle and on a …

Nudging-based data assimilation of the turbulent flow around a square cylinder

M Zauner, V Mons, O Marquet… - Journal of Fluid …, 2022 - cambridge.org
We investigate the estimation of the turbulent flow around a canonical square cylinder at
based on temporally resolved but spatially sparse velocity data and solving the unsteady …

Stochastic particle advection velocimetry (SPAV): theory, simulations, and proof-of-concept experiments

K Zhou, J Li, J Hong, SJ Grauer - Measurement Science and …, 2023 - iopscience.iop.org
Particle tracking velocimetry (PTV) is widely used to measure time-resolved, three-
dimensional velocity and pressure fields in fluid dynamics research. Inaccurate localization …

Dense velocity reconstruction with VIC-based time-segment assimilation

F Scarano, JFG Schneiders, GG Saiz… - Experiments in …, 2022 - Springer
The vortex-in-cell time-segment assimilation (VIC-TSA) method is introduced. A particle track
is obtained from a finite number of successive time samples of the tracer's position and …

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

Z Yuan, Y Wang, X Wang, J Wang - Physics of Fluids, 2023 - pubs.aip.org
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 …