Heat rate distribution in converging and diverging microchannel in presence of conjugate effect

被引:25
作者
Duryodhan, V. S. [1 ]
Singh, S. G. [2 ]
Agrawal, Amit [1 ]
机构
[1] Indian Inst Technol, Bombay 400076, Maharashtra, India
[2] Indian Inst Technol, Hyderabad 502205, Andhra Pradesh, India
关键词
Microfluidics; CFD; Varying cross section; Microchannel; Wall conduction; TEMPERATURE; FLOW;
D O I
10.1016/j.ijheatmasstransfer.2016.09.014
中图分类号
O414.1 [热力学];
学科分类号
摘要
This study pertains to understanding the effect of wall conduction on heat rate distribution through varying cross sectional area microchannel. Three-dimensional numerical simulations are performed for flow in diverging and converging microchannels with different geometrical configurations (angle: 1-8 degrees, depth: 86-200 mu m, length: 10-30 mm, solid-to-fluid thickness ratio: 1.5-4), thermo-physical properties (solid-to-fluid thermal conductivity ratio: 27-646), mass flow rate (3.3 x 10(-5)-8.3 x 10(-5) kg/s) and heat flux (2.4-9.6 W/cm(2)) conditions. It is observed that area variation and wall conduction leads to a redistribution of the supplied heat flux particularly along the flow direction. It is observed that wall conduction in converging microchannel (M = 0.028-0.064, where M is the wall conduction number) is much larger than in diverging microchannel (M = 0.006-0.024). For converging microchannel, wall conduction varies directly with the depth and solid-to-fluid thickness and conductivity ratio; whereas it exhibits inverse function with the angle, length and Reynolds number. Similarly, in diverging microchannel, wall conduction depends on all these parameters. The variation in heat rate versus surface temperature gradient exhibits two separate zones demarcating diverging and converging microchannels. The variation in heat rate is found to be well-correlated to the wall conduction number for most cases. The study is relevant because of increased application of varying cross section micro devices, and the present results should help in their thermal design. (C) 2016 Elsevier Ltd. All rights reserved.
引用
收藏
页码:1022 / 1033
页数:12
相关论文
共 18 条
[11]   Boiling heat transfer and two-phase flow of water in a single shallow microchannel with a uniform or diverging cross section [J].
Lee, Po Chang ;
Pan, Chin .
JOURNAL OF MICROMECHANICS AND MICROENGINEERING, 2008, 18 (02)
[12]   Theoretical analysis of Marangoni instability of an evaporating droplet by energy method [J].
Ha, VM ;
Lai, CL .
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 2004, 47 (17-18) :3811-3823
[13]  
Moharana M. K., 2012, P 3 EUR C MICR MICR
[14]   Optimum Nusselt Number for Simultaneously Developing Internal Flow Under Conjugate Conditions in a Square Microchannel [J].
Moharana, Manoj Kumar ;
Singh, Piyush Kumar ;
Khandekar, Sameer .
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 2012, 134 (07)
[15]   Guidelines for the Determination of Single-Phase Forced Convection Coefficients in Microchannels [J].
Morini, Gian Luca ;
Yang, Yahui .
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME, 2013, 135 (10)
[16]   Accelerated particle electrophoretic motion and separation in converging-diverging microchannels [J].
Xuan, XC ;
Xu, B ;
Li, DQ .
ANALYTICAL CHEMISTRY, 2005, 77 (14) :4323-4328
[17]   The Effect on the Nusselt Number of the Nonlinear Axial Temperature Distribution of Gas Flows Through Microtubes [J].
Yang, Yahui ;
Chalabi, Habib ;
Lorenzini, Marco ;
Morini, Gian Luca .
HEAT TRANSFER ENGINEERING, 2014, 35 (02) :159-170
[18]  
Yong J. Q, 2014, J HEAT TRANSFER, V136, P1