Numerical Simulations of Cyclic Melting and Freezing of Phase Change Material in Micro-foam

2012 ◽  
Author(s):  
Xin Hu ◽  
Soumya Patnaik
Keyword(s):  
Phase Change ◽  
Numerical Simulations ◽  
Phase Change Material ◽  
Change Material

Experimental Validation of Numerical Simulations of a Closed-Loop Thermosyphon Operating With Slurries of a Microencapsulated Phase-Change Material

2014 ◽  
Author(s):  
Alexandre Lamoureux ◽  
Bantwal R. (Rabi) Baliga
Keyword(s):  
Phase Change ◽  
Numerical Simulations ◽  
Phase Change Material ◽  
Experimental Validation ◽  
Closed Loop ◽  
Effective Properties ◽  
Control Volume ◽  
Experimental Calibration ◽  
Microencapsulated Phase Change Material ◽  
Change Material

Experimental validation and calibration of numerical simulations of a closed-loop thermosyphon operating under steady-state conditions with slurries of a microencapsulated phase-change material (MCPCM) suspended in distilled water are presented. The slurries exhibited a non-Newtonian, shear-thinning, power-law rheological behavior in the range of parameters considered; and the constants in the related model were calibrated using data from specially conducted experiments. The flows of these slurries in the problems of interest were laminar. Furthermore, the velocity and temperature differences between the dispersed and conveying phases of these slurries were negligibly small, so homogeneous models could be used for mathematical representations of the fluid flow and heat transfer phenomena. A hybrid numerical method was used in the simulations: detailed two-dimensional axisymmetric control-volume finite element (CVFEM) simulations of the heated and cooled sections of the thermosyphon were coupled with segmented quasi-one-dimensional finite volume (FVM) simulations of the other portions. The CVFEM and FVM used in this work are well-established. Thus, the verification of these methods is not addressed here. Rather, the details of the thermosyphon, effective properties of the MCPCM and slurries, overviews of the hybrid model and the aforementioned numerical methods, notes on the experimental calibration and validation, and some results are presented and discussed.

Numerical and Experimental Study of Solidification in a Spherical Shell

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
E. Assis ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Spherical Shell ◽  
Phase Change ◽  
Numerical Simulations ◽  
Phase Change Material ◽  
Void Formation ◽  
Initial State ◽  
Solidification Temperature ◽  
Irregular Boundary ◽  
The Mean ◽  
Change Material

The present study explores numerically and experimentally the process of a phase-change material (PCM) solidification in a spherical shell. At the initial state, the PCM liquid occupies 98.5% of the shell. The upper segment of 1.5% contains air, which flows in as the solidification progresses. In the experiments, a commercially available paraffin wax is used. Its properties are engaged in the numerical simulations. The investigation is performed for solidification in spherical shells of 20 mm, 40 mm, 60 mm, and 80 mm in diameter at the wall uniform temperature, which varied from 10°C to 40°C below the mean solidification temperature of the phase-change material. Transient numerical simulations are performed using the FLUENT 6.2 software and incorporate such phenomena as flow in the liquid phase, volumetric shrinkage due to solidification, and irregular boundary between the PCM and air. The numerical model is validated versus the experimental results. Shrinkage patterns and void formation are demonstrated. Dimensional analysis of the results is performed and presented as the PCM melt fractions versus the product of the Fourier and Stefan numbers. This analysis leads to a generalization that encompasses the cases considered herein.

Effect of Finned-Tube on the Enhancement of Melting Process of PCM in Eccentric Cylinders

2020 ◽  
Vol 22 (4) ◽  
pp. 975-982
Author(s):  
S. Khaldi ◽  
A. Nabil Korti ◽  
S. Abboudi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Numerical Simulations ◽  
Phase Change Material ◽  
Melting Process ◽  
Finned Tube ◽  
Eccentric Cylinders ◽  
Horizontal Cylinders ◽  
Volume Method ◽  
Change Material

AbstractThe process of melting of a phase-change material (PCM) in eccentric horizontal cylinders geometry is studied numerically. Numerical simulations are performed for symmetric melting of phase change material between the two cylinders using the finite volume method. The inner cylinder is a finned-tube to enhance the heat transfer between the inner cylinder and the PCM. Inner cylindrical is considered as hot wall while outer is insulated. These simulations show the melting process from the beginning to the end. As result, it is found that the use of fins on the inner tube increases the melting process by decreasing the time of melting by 72.72 %.

NUMERICAL STUDY OF A SOLAR GREENHOUSE DRYER WITH A PHASE-CHANGE MATERIAL AS AN ENERGY STORAGE MEDIUM

2018 ◽  
Vol 49 (6) ◽  
pp. 509-528 ◽  
Author(s):  
Orawan Aumporn ◽  
Belkacem Zeghmati ◽  
Xavier Chesneau ◽  
Serm Janjai
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Storage Medium ◽  
Solar Greenhouse ◽  
Change Material

CONTROL OF HEAT RELEASE ENERGY DURING HEATING FROM SOLID-SOLID PHASE CHANGE MATERIAL

2018 ◽  
Author(s):  
Ryohei Gotoh ◽  
Tsuyoshi Totani ◽  
Masashi Wakita ◽  
Harunori Nagata
Keyword(s):  
Phase Change ◽  
Heat Release ◽  
Phase Change Material ◽  
Solid Phase ◽  
Change Material
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