Study of the transient thermal wave heat transfer in a channel immersed in a bath of superfluid helium

Thermal wave is a very interesting phenomenon in which heat is transported in the wave mode. It is different from the ordinary Fourier heat transfer discipline in which heat is transported in the diffusive mode. In the present study, transient thermal wave (second sound wave) heat transfer in He II (superfluid helium) is numerically studied. Quantized vortices in He II, a phenomenon related to the superfluid nature, which is an important factor affecting the behavior of the thermal wave has been taken into account. The present results show that the shape of the thermal wave does not deform seriously and the amount of the heat contained in and transported by the thermal wave does not decrease as the thermal wave transmits along the channel when it is free from the quantized vortices; while the shape of the thermal wave starts to deform at the moment of the emission of the thermal wave and the amount of the heat transported by the thermal wave decreases when it is subject to the quantized vortices. The deformation is in stronger magnitude in the case of the larger heat flux. The surplus amount of the heat which cannot be carried away by the thermal wave accumulates in the thermal boundary layer formed by the dense quantized vortices and then is transferred in a diffusion-like mode. It is found that Gorter-Mellink equation is not suitable to describe the transient heat transfer process in He II.