Below a critical temperature, some fluids can present superfluid
behaviour and lose internal friction. This study presents an adequate
thermomechanical formulation that can lead to the modelling of
temperature waves of finite speed (second sound) in superfluids,
what is observed experimentally. The goal is the analysis of the influence
of the thermomechanical coupling on the propagation of temperature
waves in the superfluid component whose viscosity is zero. Due to
the thermo-mechanical coupling, density waves may induce moving
heat sources or sinks while temperature waves propagate at a different
and independent speed. In particular, turbulence in this kind of fluid can
strongly affect heat propagation. Sufficient conditions for a thermodynamic
consistent and frame invariant modelling are presented and
discussed. The main objective was to raise questions that should not
be neglected in future experimental studies. Although superfluid isgenerally considered a mixture of two fluids, one with superfluid
behaviour and one normal that gradually disappears with a decreasing
temperature, in the present study, to make the analysis simpler,
temperature was always assumed to be below critical and only the
supercritical fraction of the fluid is considered. Nevertheless, an alternative
and more complete continuum modelling can be obtained by
combining the viscous constitutive equations proposed in [6] with the
compressible fluid equations proposed in the present paper