A two-fluid-model analysis on transient, internal-convection heat transfer of He II in a vertical Gorter-Mellink duct heated at the bottom surface
✍ Scribed by Van F. Rao; Kenji Fukuda; Hideki Horie
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 967 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0011-2275
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✦ Synopsis
This paper deals with the flow and heat transfer of superfluid helium in a vertical Gorter-Mellink duct. Numerical simulation is performed using basic equations of the two-fluid model, with the dissipation due to the Gorter-Mellink two-fluid mutual friction added to the transport equation of entropy. The results indicate different patterns of thermal wave propagation induced by a stepwise heating. For a very low heat flux, the thermal energy will be transported mainly by the unique second-sound wave in He II, while for a higher heat flux it will be transported mainly by thermal diffusion. If the heat flux is higher than a limiting value, the temperature at the heated surface will increase sharply to reach the critical value for phase transition or boiling initiation. While when the heat flux is lower than the limiting value, the temperature distribution in the duct will reach an equilibrium showing either a high or a low thermal conductivity. The level of the thermal conductivity is found to be related to the level of the dissipation due to the two-fluid mutual friction, which is determined by the local temperature and heat flux. The numerically predicted limiting heat flux is also compared with the experimental data by Van Sciver, and the agreement is satisfactory.