Superfluid Dynamics, Equilibrium Conditions, and Centripetal Forces

Thermodynamics of superfluids is revisited, clarifying two points. First, the density and pressure distribution for given equilibrium velocities is obtained, with the finding that counter heat currents give rise to a pressure depression and a centripetal force. Second, it is shown that the ideal two-fluid hydro\-dynamics is simply an assembly of \textit{equilibrium conditions} -- expressions of entropy being maximal.