A Porous Medium Approach for Single-Phase Flow and Heat Transfer Modeling in Manifold Microchannel Heat Exchangers

2021 ◽  
Author(s):  
Fabio Battaglia ◽  
Raphael Kahat Mandel ◽  
Amir H Shooshtari ◽  
Michael Ohadi
Author(s):  
Fabio Battaglia ◽  
Raphael Mandel ◽  
Amir Shooshtari ◽  
Michael M. Ohadi

Abstract Manifold Microchannels have been proven to enhance thermal management in different fields, such as electronic cooling, dry cooling, and high temperature heat exchangers. Manifold-microchannels use a system of manifolds to divide a microgrooved surface into a system of manifolds, thereby reducing pressure drop and increasing heat transfer by utilizing the developing flow regime. Because of this, design of a manifold-microchannel heat exchanger requires the design of the manifold and microchannel. In some situations, a sequential design approach, where one first designs the microchannel and then the manifold — is sufficient to meet the requirements of the problem statements. The more demanding requirements of contemporary applications require manifold microchannel design to evolve and become more complex. In particular, reducing the volume and pitch of the manifold has become necessary. Reducing the volume of the manifold results in a higher flow maldistribution, and the ability to predict how maldistribution affects heat transfer rate is critical. Similarly, reducing the pitch of the manifold increases the effect of axial conduction in the solid, and understanding the effect on heat transfer is important. To those ends, this work shows a porous medium approach for single-phase flow in manifold microchannel, which allows to predict pressure drop, maldistribution, axial conduction, and heat transfer rate with a much smaller computational demand when compared to a full 3D simulation, while guaranteeing very similar results.


Author(s):  
Devin Pellicone ◽  
Alfonso Ortega ◽  
Marcelo del Valle ◽  
Steven Schon

Advances in concentrating photovoltaics technology have generated a need for more effective thermal management techniques. Research in photovoltaics has shown that there is a more than 50% decrease in PV cell efficiency when operating temperatures approach 60°C. It is estimated that a waste heat load in excess of 500 W/cm2 will need to be dissipated at a solar concentration of 10,000 suns. Mini- and micro-scale heat exchangers provide the means for large heat transfer coefficients with single phase flow due to the inverse proportionality of Nusselt number with respect to the hydraulic diameter. For very high heat flux situations, single phase forced convection in micro-channels may not be sufficient and hence convective flow boiling in small scale heat exchangers has gained wider scrutiny due to the much higher achievable heat transfer coefficients due to latent heat of vaporization and convective boiling. The purpose of this investigation is to explore a practical and accurate modeling approach for simulating multiphase flow and heat transfer in mini- and micro-channel heat exchangers. The work is specifically aimed at providing a modeling tool to assist in the design of a mini/micro-scale stacked heat exchanger to operate in the boiling regime. The flow side energy and momentum equations have been implemented using a one-dimensional homogeneous approach, with local heat transfer coefficients and friction factors supplied by literature correlations. The channel flow solver has been implemented in MATLAB™ and embedded within the COMSOL™ FEM solver which is used to model the solid side conduction problem. The COMSOL environment allows for parameterization of design variables leading to a fully customizable model of a two-phase heat exchanger.


2010 ◽  
Vol 34 (8) ◽  
pp. 1309-1315 ◽  
Author(s):  
Youmin Xi ◽  
Jianzu Yu ◽  
Yongqi Xie ◽  
Hongxia Gao

2017 ◽  
Vol 115 ◽  
pp. 793-814 ◽  
Author(s):  
Amirah M. Sahar ◽  
Jan Wissink ◽  
Mohamed M. Mahmoud ◽  
Tassos G. Karayiannis ◽  
Mohamad S. Ashrul Ishak

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