Numerical evidence of universal scaling for the scalar variance spectrum in forced homogeneous turbulence

Jean-Baptiste Lagaert (1, 2) , Guillaume Balarac (1) , Georges-Henri Cottet (2)

1 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]
2 EDP - Equations aux Dérivées Partielles

In this paper, the spectrum of high Schmidt number passive scalar in forced homogeneous isotropic turbulence is studied through direct numerical simulations. An hybrid spectral-particle method is used with a finer resolution of the scalar than of the momentum and large time-steps. This approach enables to perform a systematic analysis over a wide range of Schmidt numbers. Our results recover the theoretical scaling for the variance scalar spectrum, and its relationship with the value of the Schmidt number, for large, intermediate and small scales. The influence of the form of the scalar forcing is also discussed.

Mots clés: scalar variance; turbulent flow; univsersal scaling; particle method; spectral method; hybrid method

Domaines: Analyse numérique [math.NA]

Jean-Baptiste Lagaert, Guillaume Balarac, Georges-Henri Cottet. Numerical evidence of universal scaling for the scalar variance spectrum in forced homogeneous turbulence. 2012. ⟨hal-00769144v2⟩