Numerical Study on Phase Change of Water Flowing Across Two Heated Circular Cylinders in Tandem Arrangement

2016 ◽  
Vol 46 (7) ◽  
pp. 656-680
Author(s):  
B.K. Dhar ◽  
S.K. Mahapatra ◽  
S.K. Maharana ◽  
A. Sarkar ◽  
S.S. Sahoo
Keyword(s):  
Phase Change ◽  
Numerical Study ◽  
Circular Cylinders ◽  
Tandem Arrangement

scholarly journals Numerical study on phase change of water flowing across two heated rotating circular cylinders in tandem arrangement

2016 ◽  
Vol 8 (4) ◽  
pp. 201-212
Author(s):  
BK Dhar ◽  
SK Mahapatra ◽  
SK Maharana ◽  
A Sarkar ◽  
SS Sahoo
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Phase Change ◽  
Numerical Study ◽  
Heat Transfer Analysis ◽  
Circular Cylinders ◽  
Transfer Coefficients ◽  
Tandem Arrangement ◽  
Flow And Heat Transfer ◽  
An Array Of Cylinders

The problems of fluid flow and heat transfer phenomena over an array of cylinders are quite prominent in fluid dynamics and industry applications. The current work focuses on fluid flow and heat transfer analysis over two heated rotating cylinders arranged in tandem. The flow of water over heated cylinders faces a phenomenon of phase change from liquid (water) to vapor phase (steam). The mechanism of this phase change is studied through a numerical simulation supplemented with verification of the code and validation. The problem is simulated when flows from two cylinders in a tandem arrangement become interacting and non-interacting. The Eulerian model is used during simulation to comprehend the multiphase phenomena. The volume fractions of both the phases such as water and vapor and heat transfer coefficients of both the cylinders have been computed and presented as findings of the problem. The mass and heat transfer mechanism is unidirectional from one phase to the other phase. The vapor fraction of each phase is to be observed and compared when three different rotations are given to the two cylinders immersed in a turbulent flow of water.

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

Numerical Performances Study of Curved Photovoltaic Panel Integrated with Phase Change Material

2020 ◽  
Vol 22 (4) ◽  
pp. 1439-1452
Author(s):  
Mohamed L. Benlekkam ◽  
Driss Nehari ◽  
Habib Y. Madani
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Numerical Data ◽  
Navier Stokes ◽  
Photovoltaic Panel ◽  
Pv Panel ◽  
Energy Equations ◽  
Solid Liquid ◽  
Change Material

AbstractThe temperature rise of photovoltaic’s cells deteriorates its conversion efficiency. The use of a phase change material (PCM) layer linked to a curved photovoltaic PV panel so-called PV-mirror to control its temperature elevation has been numerically studied. This numerical study was carried out to explore the effect of inner fins length on the thermal and electrical improvement of curved PV panel. So a numerical model of heat transfer with solid-liquid phase change has been developed to solve the Navier–Stokes and energy equations. The predicted results are validated with an available experimental and numerical data. Results shows that the use of fins improve the thermal load distribution presented on the upper front of PV/PCM system and maintained it under 42°C compared with another without fins and enhance the PV cells efficiency by more than 2%.

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.

scholarly journals Numerical Simulation of the Impact of the Heat Source Position on Melting of a Nano-Enhanced Phase Change Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1425
Author(s):  
Tarek Bouzennada ◽  
Farid Mechighel ◽  
Kaouther Ghachem ◽  
Lioua Kolsi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Commercial Code ◽  
Tube Position ◽  
The Impact ◽  
Change Material

A 2D-symmetric numerical study of a new design of Nano-Enhanced Phase change material (NEPCM)-filled enclosure is presented in this paper. The enclosure is equipped with an inner tube allowing the circulation of the heat transfer fluid (HTF); n-Octadecane is chosen as phase change material (PCM). Comsol-Multiphysics commercial code was used to solve the governing equations. This study has been performed to examine the heat distribution and melting rate under the influence of the inner-tube position and the concentration of the nanoparticles dispersed in the PCM. The inner tube was located at three different vertical positions and the nanoparticle concentration was varied from 0 to 0.06. The results revealed that both heat transfer/melting rates are improved when the inner tube is located at the bottom region of the enclosure and by increasing the concentration of the nanoparticles. The addition of the nanoparticles enhances the heat transfer due to the considerable increase in conductivity. On the other hand, by placing the tube in the bottom area of the enclosure, the liquid PCM gets a wider space, allowing the intensification of the natural convection.

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