Bayesian optimisation of RANS simulation with ensemble-based variational method in convergent-divergent channel
Article dans une revue avec comité de lecture
Date
2019Journal
Journal of TurbulenceAbstract
This paper investigates the applicability of a hybrid data assimilation approach, namely ensemble-based variational method (EnVar), to optimise Reynolds Averaged Navier-Stokes (RANS) simulations in convergent-divergent channel from the perspective of Bayesian inference. Concretely, the ensemble-based variational method is applied to infer the inlet velocity and turbulence model corrections by assimilating Direct Numerical Simulation (DNS) results or limited experimental data. The approach is first adopted to infer the inlet velocity profile for the WallTurb Bump and Venturi geometry. The improvement can be achieved near the inlet region for the bump, but for Venturi in light of the view field limited in adverse pressure gradient region, the observation space is not sensitive to the perturbation of inlet condition. In a second step, the model corrections in k − ω SST model are investigated by assimilating the limited sparse experimental data. With the inferred model corrections, the predictions on both velocity and turbulent kinetic energy (TKE) get improved. The results indicate that the ensemble-based variational method is efficient in inferring unknown quantities of both low dimension (D=20) and high dimension (D=2400) with small ensemble size robustly and non-intrusively. This approach could prove very useful for Bayesian inference or optimisation in CFD problems.
Files in this item
Related items
Showing items related by title, author, creator and subject.
-
Communication avec acteThis paper investigates the application of data-driven approach to the optimization of cavitating flow simulations. An evaluation of the performance of commonly used RANS models (k-e, k-w and k-w SST) is presented by ...
-
Article dans une revue avec comité de lectureSHI, Lei; WANG, Yefang; ZHANG, Desheng; BAYEUL-LAINÉ, Annie-Claude; COUTIER-DELGOSHA, Olivier (Elsevier BV, 2022-11)The pitching airfoils, applied to the vertical axis turbines and propellers, are critical to extract more energy from the environment. At retreating side, when the airfoil blunt leading edge becomes the trailing edge, the ...
-
Article dans une revue avec comité de lectureSHI, Lei; ZHANG, Desheng; BAYEUL-LAINÉ, Annie-Claude; COUTIER-DELGOSHA, Olivier (Elsevier BV, 2023-07)The goal of the present work is to investigate the influence of several parameters on the performance and flow structures of reversed pitching airfoils. Firstly, the effect of the turbulence model is evaluated, and the ...
-
Article dans une revue avec comité de lectureSHI, Lei; ZHANG, Desheng; BAYEUL-LAINÉ, Annie-Claude; COUTIER-DELGOSHA, Olivier (Elsevier BV, 2023-11)The performance and unsteady vortical flows of a 2-bladed cycloidal propeller are investigated using the SST γ �� Reθt transition model, under different pitch-pivot-point and blade camber conditions. Firstly, it shows ...
-
Article dans une revue avec comité de lectureCAIGNAERT, Guy; BOIS, Gérard; LEROUX, Jean-Baptiste; COUTIER-DELGOSHA, Olivier (American Society of Mechanical Engineers, 2012)Effects of the blade number on the performance of a rocket engine turbopump inducer are investigated in the present paper. For that purpose, two inducers characterized by three blades and five blades, respectively, were ...