Vortex stretching and a modified zeroth law for the incompressible 3D Navier-Stokes equations.

We consider the 3D incompressible Navier-Stokes equations under the following $2+\frac{1}{2}$-dimensional situation: small-scale horizontal vortex blob being stretched by large-scale, anti-parallel pairs of vertical vortex tubes. We prove a modified version of the zeroth law induced by such vortex-stretching.