Local interactions in renormalization methods for Navier-Stokes turbulence.

Abstract

Two distinct renormalization-group (RNG) approaches have been applied to Navier-Stokes turbulence: \ensuremath{\epsilon}-RNG and recursive RNG. \ensuremath{\epsilon}-RNG takes into account only nonlocal interactions and utilizes an infinitesimal subgrid (unresolvable scale) shell limit. Recursive RNG takes into account both nonlocal and local interactions and does not require an infinitesimal subgrid shell limit to be taken. The role of local interactions and the introduction of RNG-induced nonlinearities are discussed and clarified.