scholarly journals Comparison of simulated and experimental results of temperature distribution in a closed two-phase thermosyphon cooling system

2017 ◽  
Vol 278 ◽  
pp. 012022
Author(s):  
E Shaanika ◽  
K Yamaguchi ◽  
M Miki ◽  
T Ida ◽  
M Izumi ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Cooling System ◽  
Experimental Results ◽  
Two Phase

scholarly journals Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3634
Author(s):  
Grzegorz Czerwiński ◽  
Jerzy Wołoszyn
Keyword(s):  
Mass Transfer ◽  
Phase Change ◽  
Heat Dissipation ◽  
Cooling System ◽  
Numerical Study ◽  
Relaxation Parameter ◽  
Phase Changes ◽  
Transfer Time ◽  
Two Phase ◽  
Time Relaxation

With the increasing trend toward the miniaturization of electronic devices, the issue of heat dissipation becomes essential. The use of phase changes in a two-phase closed thermosyphon (TPCT) enables a significant reduction in the heat generated even at high temperatures. In this paper, we propose a modification of the evaporation–condensation model implemented in ANSYS Fluent. The modification was to manipulate the value of the mass transfer time relaxation parameter for evaporation and condensation. The developed model in the form of a UDF script allowed the introduction of additional source equations, and the obtained solution is compared with the results available in the literature. The variable value of the mass transfer time relaxation parameter during condensation rc depending on the density of the liquid and vapour phase was taken into account in the calculations. However, compared to previous numerical studies, more accurate modelling of the phase change phenomenon of the medium in the thermosyphon was possible by adopting a mass transfer time relaxation parameter during evaporation re = 1. The assumption of ten-fold higher values resulted in overestimated temperature values in all sections of the thermosyphon. Hence, the coefficient re should be selected individually depending on the case under study. A too large value may cause difficulties in obtaining the convergence of solutions, which, in the case of numerical grids with many elements (especially three-dimensional), significantly increases the computation time.

Random Forces Resulting From Internal Two-Phase Flow on Bends and Tees

2006 ◽  
Author(s):  
E. de Langre ◽  
J. L. Riverin ◽  
M. J. Pettigrew
Keyword(s):  
Two Phase Flow ◽  
Experimental Results ◽  
Time Dependent ◽  
Phase Flow ◽  
Water Mixture ◽  
Dimensionless Form ◽  
Two Phase ◽  
Practical Applications ◽  
Random Forces

The time dependent forces resulting from a two-phase air-water mixture flowing in an elbow and a tee are measured. Their magnitudes as well as their spectral contents are analyzed. Comparison is made with previous experimental results on similar systems. For practical applications a dimensionless form is proposed to relate the characteristics of these forces to the parameters defining the flow and the geometry of the piping.

A Pumped Two-Phase Cooling System for Spacecraft

1983 ◽  
Author(s):  
S. Ollendorf ◽  
F. A. Costello
Keyword(s):  
Cooling System ◽  
Two Phase ◽  
Two Phase Cooling

Evaporation of Single Drops of n-Pentane/n-Hexane Mixtures in Water

1992 ◽  
Vol 114 (4) ◽  
pp. 965-971 ◽  
Author(s):  
H. Shimaoka ◽  
Y. H. Mori
Keyword(s):  
Heat Transfer ◽  
Temperature Difference ◽  
Vapor Bubble ◽  
Experimental Results ◽  
Rise Velocity ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Transfer Characteristics ◽  
Preceding Work ◽  
Liquid Vapor

The evaporation of isolated drops (2.1−3.0 mm diameter) of nonazeotropic n-pentane/n-hexane mixtures in the medium of water was observed under pressures of 0.11−0.46 MPa and temperature differences up to 27 K. The mole fractions of n-pentane, x, in the mixtures were set at 0.9, 0.5, 0.1, and 0, to be completed by the condition x = 1 set in a preceding work (Shimaoka and Mori, 1990). Experimental results are presented in terms of the instantaneous rise velocity of, and an expression of instantaneous heat transfer to, each drop evaporating and thereby transforming into a liquid/vapor two-phase bubble and finally into a vapor bubble. The dependencies of the heat transfer characteristics on the pressure, the temperature difference, and x are discussed.

scholarly journals Shock Phenomena in a One-component Two-phase Bubbly Flow : 1st Report, Experimental Results on Transient Pressure Profiles

1986 ◽  
Vol 29 (258) ◽  
pp. 4235-4240
Author(s):  
Terushige FUJII ◽  
Koji AKAGAWA ◽  
Nobuyuki TAKENAKA ◽  
Sadao TSUBOKURA ◽  
Yoichi HIRAOKA ◽  
...  
Keyword(s):  
Bubbly Flow ◽  
Experimental Results ◽  
Transient Pressure ◽  
Two Phase ◽  
Pressure Profiles

Model Predictive Control of a Pumped Two-Phase Cooling System With Microchannel Heat Exchangers

2018 ◽  
Author(s):  
Oyuna Angatkina ◽  
Andrew Alleyne
Keyword(s):  
Heat Flux ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Heat Exchangers ◽  
Cooling System ◽  
High Heat ◽  
High Heat Flux ◽  
Two Phase ◽  
Cooling Systems ◽  
Two Phase Cooling

Two-phase cooling systems provide a viable technology for high–heat flux rejection in electronic systems. They provide high cooling capacity and uniform surface temperature. However, a major restriction of their application is the critical heat flux condition (CHF). This work presents model predictive control (MPC) design for CHF avoidance in two-phase pump driven cooling systems. The system under study includes multiple microchannel heat exchangers in series. The MPC controller performance is compared to the performance of a baseline PI controller. Simulation results show that while both controllers are able to maintain the two-phase cooling system below CHF, MPC has significant reduction in power consumption compared to the baseline controller.

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