Anisotropic linear forcing for synthetic turbulence generation in hybrid RANS/LES modelling
Résumé
A new body force is proposed, aiming at imposing to a large eddy simulation low order statistics in some specific regions where the forcing is applied. The forced LES presents a realistic turbulence with imposed mean velocity and Reynolds stress tensor of any anisotropy. It is emphasized that this new forcing – the Anisotropic Linear Forcing (ALF) – generalizes several body forces proposed in the past decade. The influence of the parameters of the forcing is discussed.
An application of ALF for synthetic turbulence generation in zonal RANS/LES computation of channel flow is presented. The method enables an efficient spatial developpement of the flow in the LES domain, without prescribing any fluctuations at the inlet boundary.