Heat Transfer in Liquid Helium II by Internal Convection

1948 ◽  
Vol 74 (9) ◽  
pp. 1148-1156 ◽  
Author(s):  
F. London ◽  
P. R. Zilsel
1955 ◽  
Vol 8 (2) ◽  
pp. 206 ◽  
Author(s):  
PG Klemens

In narrow channels (~10?4 cm) the observed heat transport is considerably larger than calculated by the internal convection theory. It is suggested that, because of the anisotropy of the distribution cf phonons in the channel walls resulting from the temperature gradient, the normal fluid in the immediate vicinity of the walls is not at rest but flows towards the colder region. The magnitude of the resulting heat transport is in reasonable agreement with the observed discrepancy.


Physica ◽  
1958 ◽  
Vol 24 ◽  
pp. S145 ◽  
Author(s):  
L.J. Challis ◽  
J. Wilks

1966 ◽  
Vol 88 (4) ◽  
pp. 343-349 ◽  
Author(s):  
W. J. Rivers ◽  
P. W. McFadden

Free-convection heat transfer from a solid surface to liquid Helium II in the presence of a film of either liquid Helium I or helium gas is analyzed mathematically. The analysis includes two heater shapes, a vertical flat plate and a horizontal circular cylinder, each with an isothermal surface. The integral forms of the boundary-layer equations are used to describe the heat transfer and fluid flow processes that occur within the film. The velocity and temperature profiles within the film are approximated by fourth degree polynomials whose coefficients were evaluated by applying a system of boundary conditions which were derived in the usual fashion but are based on assumed discontinuities in both the velocity and temperature profiles at the film-Helium II interface. Calculated results, which include the film thickness, the heat transfer coefficient, and the mass flow in the film, are presented and discussed.


The problem of heat transfer at a wall bounding a half-space ( z > 0) containing liquid helium II is considered. The helium is modelled as a two-fluid continuum (after Landau & Lifshitz) with both relaxation and healing terms incorporated into the governing equations. The heat transfer is taken to be small so that the problem can be treated as the perturbation of the equilibrium state (i. e. at zero heat transfer). It is shown that if the relaxation coefficient varies as (superfluid density) - m (1 > m ≽ 1/2) then the superfluid velocity behaves like cz 2 m -1 as z → 0. The constant c can be obtained by invoking a scaling property of the full equations. It is found that the healing parameter can be scaled out of the full equations although c can be found explicitly for small healing: c , and the related temperature at the wall, are therefore known for all values of the healing coefficient. These results reduce to those obtained by Clark (1963) when healing and relaxation are ignored.


Measurements have been made of the thermal boundary resistance between liquid helium II and copper, lead and quartz, also between copper and liquid helium II at different densities. It is found that the dependence of the heat flow on the density of the helium is markedly different from that predicted by Khalatnikov (1952). According to this author, the transfer of heat from the solid surface to the helium takes place by the radiation of phonons, rather as would be the case between two dielectric solids. However, Khalatnikov does not take account of the fact that the layer of helium close to the solid has a much higher density than the bulk liquid. An analysis has been made of the effect of this dense layer, and the dependence of the heat flow on the density of the bulk helium found to be much closer to that observed experimentally. The experimental results using different solid materials suggest that, in metals at least, some other mechanism of heat transfer may be involved.


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