Heat Transfer In Bath Research Articles

Two step phase transition model of heat transfer in bath of subcooled superfluid helium

Heat transfer in a bath of subcooled superfluid helium is different if compared with that in other coolants, which is mainly related to the superfluid characteristics and also the three phases of gas helium (GHe), helium I liquid (HeI) and subcooled helium II liquid (HeIIp). A two step phase transition model is developed, in which the interface phenomena of GHe/HeI and HeI/HeII are considered. The model explains experimental results well.

Pressure effect on the heat transfer in bath of superfluid helium

Considering the basic heat transfer rules of superfluid helium and the phase diagram of helium, pressure effects on heat transfer to HeII are especially studied. If the bath pressure is less than λ-Pressure ( P λ ), special peak heat flux density relations are shown to correlate bath pressure, hydrostatic head and modified pressure items (van der Waals pressure and fountain pressure). If the bath pressure is greater than λ-pressure( P>P λ ), a generalized formula of peak flux density of HeIIp bath is shown.

An integrated mathematical model of float process

Abstract An integrated mathematical model of the float process has been developed. This integrated model consists of a glass ribbon forming model, a float bath heat transfer model and a molten tin flow model. In the float process, glass ribbon forming and heat transfer in the bath influence each other. That is, the viscosity of the glass ribbon depends strongly on its temperature. Also, molten tin flow, which plays an important role in the bath heat transfer, is caused by glass ribbon traction and buoyancy convection. Therefore these three models are linked with one another. In the first model, the molten glass flow on the molten tin is simulated as viscous fluid flow. In the second model, three-dimensional radiative heat transfer is simulated. In the third model, three-dimensional turbulent flow of the molten tin is simulated. It is found that the simulated results are in good agreement with the measurements in the actual process. This integrated model can be used to study the mechanism in the float process, and moreover to optimize the operating conditions and to design float baths.