EIGENVALUE PROBLEMS IN 3-DIMENSIONAL EULER FLOWS

A simple analysis shows that there are two eigenvalue problems associa ted with vorticity. Dynamically, the vorticity tends to be a simultane ous eigenvector of the rate-of-strain tensor S and the pressure hessia n P at the point of maximum enstrophy, as shown in the numerical simul ations. This suggests that intense vortex stretching occurs at particu lar fluid particles. Indeed, high vorticity regions are more localized in Lagrangian marker space than in physical space. It is also shown t hat the P alignment holds valid even kinematically for random fields.