title: Quasiconservation laws for compressible three-dimensional Navier-Stokes flow.
abstract: We formulate the quasi-Lagrangian fluid transport dynamics of mass density ρ and the projection q=ω·∇ρ of the vorticity ω onto the density gradient, as determined by the three-dimensional compressible Navier-Stokes equations for an ideal gas, although the results apply for an arbitrary equation of state. It turns out that the quasi-Lagrangian transport of q cannot cross a level set of ρ. That is, in this formulation, level sets of ρ (isopycnals) are impermeable to the transport of the projection q.
authors.affiliation: Department of Mathematics, Imperial College, London SW7 2AZ, United Kingdom. j.d.gibbon@ic.ac.uk
authors.forename: J D
authors.initials: JD
authors.lastname: Gibbon
authors.forename: D D
authors.initials: DD
authors.lastname: Holm