scholarly journals Heat flux during boiling of superfluid helium inside a porous body based on a two-fluid model

2021 ◽  
Vol 2088 (1) ◽  
pp. 012038
Author(s):  
Yu Yu Puzina ◽  
A P Kryukov
Keyword(s):  
Heat Flux ◽  
Porous Structure ◽  
Superfluid Helium ◽  
Fluid Model ◽  
Quantitative Agreement ◽  
Molecular Kinetic Theory ◽  
Two Fluid Model ◽  
Experimental Values ◽  
Semi Empirical ◽  
Two Fluid

Abstract The calculation of the recovery heat flux density is considered for superfluid helium boiling on the cylindrical heater inside porous structure. System of equations is based on the methods of continuum mechanics and molecular kinetic theory. The new type of boundary condition on the vapor-liquid interface based on the two-fluid model is formulated. Heat transfer in a free liquid is described by the Gorter-Mellink semi-empirical theory. Inside the porous structure the processes is discussed by the two-fluid model and filtration equation. Experimental data on the boiling of superfluid helium inside the porous structure are interpreted based on the formulated mathematical model. The qualitative and in some cases quantitative agreement between the calculated and experimental values of the recovery heat flux were obtained in the considered range of parameters

Comments on the article: ‘The two-fluid model of the helium film’

1973 ◽  
Vol 333 (1593) ◽  
pp. 261-263 ◽  
Keyword(s):  
Superfluid Helium ◽  
Fluid Model ◽  
Convection Velocity ◽  
Thermodynamic Approach ◽  
Helium Film ◽  
Helium Films ◽  
Third Sound ◽  
Superfluid Flow ◽  
Two Fluid Model ◽  
Two Fluid

It is argued that the thermodynamic approach used by Goodstein and Saffman in their theory of thin superfluid helium films is incorrect. Their theory does not explain Keller’s experiment. The value they obtained for the convection velocity of third sound in a film with superfluid flow is consequently unfounded theoretically. Their calculation of third sound attenuation is shown to be incomplete.

CFD Analysis on Wall Boiling Model During Subcooled Boiling in Vertical Narrow Rectangular Channel

2018 ◽  
Author(s):  
Tingting Ren ◽  
Changqi Yan ◽  
Meiyue Yan ◽  
Shengzhi Yu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fluid Model ◽  
Rectangular Channel ◽  
Subcooled Boiling ◽  
Site Density ◽  
Rectangular Channels ◽  
Two Fluid Model ◽  
Nucleate Site ◽  
Two Fluid

Two-fluid model is a common method to simulate the subcooled flow boiling heat transfer, in which the wall boiling model is mainly used for the partition of wall heat flux and the mass transfer between two phases on the wall. The model determines the amount of vapor phase and predicts the cross-sectional void fraction in the channel, nucleate site density and bubble departure diameter play an important role in the accurate prediction of wall boiling model. Eulerian two-fluid model coupled with Rensselaer Polytechnic Institute (RPI) wall boiling model is employed to simulate the heat transfer characteristics and boiling phenomena in vertical narrow rectangular channels by using FLUENT code. Based on the experimental data of subcooled boiling in vertical narrow rectangular channel, different combinations of nucleate site density and bubble departure diameter correlations are used to calculate under different conditions of heat flux and inlet subcooling. Comparing the calculated heat transfer coefficients along the vertical height with experimental results, it can be found that these two parameters have a significant effect on the subcooled boiling heat transfer in narrow rectangular channels. Different parameter combinations lead to differences in wall heat flux distribution, different heat flux and inlet subcooling also have different effects on these models, which eventually lead to different evaporative heat flux, thus affecting the prediction of void fraction.

Thermodynamic excess functions of regular and related solutions according to some equations of state based on the perturbed hard sphere model

1973 ◽  
Vol 26 (10) ◽  
pp. 2071 ◽  
Author(s):  
DK Astin ◽  
ID Watson
Keyword(s):  
Equation Of State ◽  
Hard Sphere ◽  
Equations Of State ◽  
Fluid Model ◽  
Quantitative Agreement ◽  
Excess Functions ◽  
Hard Sphere Model ◽  
Thermodynamic Excess Functions ◽  
Two Fluid Model ◽  
Two Fluid

The excess thermodynamic functions of 12 mixtures, each representative of a certain type of system, have been calculated by means of the van der Waals, Frisch,1 and Carnahan and Starling2 equation of state, in conjunction with one-fluid and two-fluid models of conformal mixtures. In addition, the equation of state of hard sphere mixtures of Mansoori et al.3 has been used. Though none of the approaches give quantitative agreement for any of the systems considered, they all give a qualitative account which broadly reflect the trends in behaviour. In the cases where it is appropriate to comment on the qualitative accuracy the two-fluid model, used with either the Frisch or Carnahan and Starling equation of state, shows a slight superiority to the others.

scholarly journals Edge turbulence and divertor heat flux width simulations of Alcator C-Mod discharges using an electromagnetic two-fluid model

2017 ◽  
Vol 57 (11) ◽  
pp. 116025 ◽  
Author(s):  
B. Chen ◽  
X.Q. Xu ◽  
T.Y. Xia ◽  
M. Porkolab ◽  
E. Edlund ◽  
...  
Keyword(s):  
Heat Flux ◽  
Fluid Model ◽  
Two Fluid Model ◽  
Two Fluid

scholarly journals Wave heating of the solar atmosphere without shocks

2020 ◽  
Vol 635 ◽  
pp. A28 ◽  
Author(s):  
D. Wójcik ◽  
B. Kuźma ◽  
K. Murawski ◽  
Z. E. Musielak
Keyword(s):  
Solar Atmosphere ◽  
Fluid Model ◽  
Local Heating ◽  
Energy Losses ◽  
Solar Convection ◽  
Wave Heating ◽  
Two Fluid Model ◽  
Semi Empirical ◽  
The Waves ◽  
Two Fluid

Context. We investigate the wave heating problem of a solar quiet region and present its plausible solution without involving shock formation. Aims. We aim to use numerical simulations to study wave propagation and dissipation in the partially ionized solar atmosphere, whose model includes both neutrals and ions. Methods. We used a 2.5D two-fluid model of the solar atmosphere to study the wave generation and propagation. The source of these waves is the solar convection located beneath the photosphere. Results. The energy carried by the waves is dissipated through ion-neutral collisions, which replace shocks used in some previous studies as the main source of local heating in quiet regions. Conclusions. We show that the resulting wave dissipation is sufficient to balance radiative and thermal energy losses, and to sustain a quasi-stationary atmosphere whose averaged temperature profile agrees well with the observationally based semi-empirical model of Avrett & Loeser (2008, ApJS, 175, 229).

scholarly journals A PISO-like algorithm to simulate superfluid helium flow with the two-fluid model

2015 ◽  
Vol 187 ◽  
pp. 20-28 ◽  
Author(s):  
Cyprien Soulaine ◽  
Michel Quintard ◽  
Hervé Allain ◽  
Bertrand Baudouy ◽  
Rob Van Weelderen
Keyword(s):  
Superfluid Helium ◽  
Fluid Model ◽  
Helium Flow ◽  
Two Fluid Model ◽  
Two Fluid
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