Numerical simulations of the Lagrangian Averaged Navier-Stokes (LANS) equations

The modeling capabilities of the Lagrangian Aver-aged Navier-Stokes-a equations (LANS-a) is inves-tigated in statistically stationary three-dimensional homogeneous and isotropic turbulence. The predic-tive abilities of the LANS-a equations are analyzed by comparison with DNS data. Two different forcing techniques were implemented to model the energet-ics of the energy containing scales. The resolved flow is examined by comparison of the energy spectra of the LANS-a and the DNS computations; further-more, the correlation between the vorticity and the eigenvectors of the rate of the resolved strain tensor is studied. We find that the LANS-a equations cap-tures the gross features of the flow while the wave activity below a given scale a is filtered by the non-linear dispersion.