Emphasizing structure in the study of 3D incompressible fluid motion
Incompressible fluid motion without friction (which would, if friction were considered, come from the billiard effect creating Brownian motion) is governed by the Euler pde (1752-57).
This randomness is still present beneath the surface in the Euler pde because an integral operator which is an inverse to exterior d is used in Euler and the one used is actually described by Brownian motion .
The goal is to derive apriori bounds for Euler and Euler with friction (derived by Navier 1822 & Stokes 1846 ),both incompressible. This , by using Random geometry together with the properties of transport of related geometric structures. For example , the circulation around a null homologous circle moving with the fluid ( Lord Kelvin 1867using Stokes theorem and Helmhotz below )giving fluid motion invariant functions on those components of the free loop space ) . Also the angular momentum exact two form of the fluid motion ( Helmhotz vorticity 1858 , which is transported by the Euler pde). Finally the constant in time , zero curvature of the metric obtained by the motion’s rearranging of the background metric on triply periodic Euclidean three space.