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A kinematic subgrid scale model for large eddy simulation of turbulence-generated sound

Huadong Yao (Institutionen för tillämpad mekanik, Strömningslära) ; Guo-Wei He
Journal of turbulence (1468-5248). Vol. 10 (2009), 19, p. 1-14.
[Artikel, refereegranskad vetenskaplig]

In the hybrid approach of large-eddy simulation (LES) and Lighthill's acoustic analogy for turbulence-generated sound, the turbulence source fields are obtained using an LES and the turbulence-generated sound at far fields is calculated from Lighthill's acoustic analogy. As only the velocity fields at resolved scales are available from the LES, the Lighthill stress tensor, serving as a source term in Lighthill's acoustic equation, has to be evaluated from the resolved velocity fields. As a result, the contribution from the unresolved velocity fields is missing in the conventional LES. The sound of missing scales is shown to be important and hence needs to be modeled. The present study proposes a kinematic subgrid-scale (SGS) model which recasts the unresolved velocity fields into Lighthill's stress tensors. A kinematic simulation is used to construct the unresolved velocity fields with the imposed temporal statistics, which is consistent with the random sweeping hypothesis. The kinematic SGS model is used to calculate sound power spectra from isotropic turbulence and yields an improved result: the missing portion of the sound power spectra is approximately recovered in the LES

Denna post skapades 2014-09-18.
CPL Pubid: 202905


Institutioner (Chalmers)

Institutionen för tillämpad mekanik, Strömningslära



Chalmers infrastruktur