Inflow and initial conditions for direct numerical simulation based on adjoint data assimilation

JOURNAL OF COMPUTATIONAL PHYSICS

卷:242

Article

Gronskis, A.¹  Heitz, D.^2,3  Memin, E.¹ 

[1] INRIA Rennes Bretagne Atlantique, F-35042 Rennes, France

[2] Irstea, UR TERE, F-35044 Rennes, France

[3] Univ Europeenne Bretagne, Rennes, France

关键词: Data driven simulation;    Variational assimilation;    Automatic differentiation;    Adjoint equations;    Inlet condition specification;    PIV;    Wake flow;   

DOI  :  10.1016/j.jcp.2013.01.051

来源: Elsevier

【 摘 要 】

A method for generating inflow conditions for direct numerical simulations (DNS) of spatially-developing flows is presented. The proposed method is based on variational data assimilation and adjoint-based optimization. The estimation is conducted through an iterative process involving a forward integration of a given dynamical model followed by a backward integration of an adjoint system defined by the adjoint of the discrete scheme associated to the dynamical system. The approach's robustness is evaluated on two synthetic velocity field sequences provided by numerical simulation of a mixing layer and a wake flow behind a cylinder. The performance of the technique is also illustrated in a real world application by using noisy large scale PIV measurements. This method denoises experimental velocity fields and reconstructs a continuous trajectory of motion fields from discrete and unstable measurements. (C) 2013 Elsevier Inc. All rights reserved.

【 授权许可】

Free