  The decomposition of the energy of a compressible fluid parcel into slow
(deterministic) and fast (stochastic) components is interpreted as a stochastic
Hamiltonian interacting particle system (HIPS). It is shown that the
McKean-Vlasov equation associated to the mean field limit yields the barotropic
Navier-Stokes equation with density dependent viscosity. Capillary forces can
also be treated by this approach. Due to the Hamiltonian structure the mean
field system satisfies a Kelvin circulation theorem along stochastic Lagrangian
paths.
