0
research-article

Effect of Bifurcation on Thermal Characteristics of Convergent-Divergent Shaped Microchannel

[+] Author and Article Information
Pankaj Srivastava

Instruments R & D Establishment, Defence R & D Organisation, Dehradun - 248008, India
pankaj_knit@rediffmail.com

Anupam Dewan

Department of Applied Mechanics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi - 110016, India
adewan@am.iitd.ac.in

1Corresponding author.

ASME doi:10.1115/1.4039088 History: Received July 20, 2017; Revised January 06, 2018

Abstract

A microchannel heat sink with convergent-divergent shape and bifurcation is presented and flow and heat transfer characteristics are analyzed for Re ranging from 120 to 900. The three-dimensional governing equations for the conjugate heat transfer with temperature-dependent solid and fluid properties are solved using the finite volume method. Comparisons have been carried out for four cases, namely, rectangular shape with and without bifurcation and convergent-divergent (CD) shape with and without bifurcation. The pressure drop, flow structure and average Nusselt number are analyzed in detail, and thermal resistance and overall performance are compared. It is shown that the CD shape with bifurcation has more uniform and lower temperature at the bottom wall and better heat transfer performance compared to other geometries. The heat transfer augmentation in the CD shape microchannel with bifurcation can be attributed not only to the accelerated and redirected flow towards the constant cross-section segment but also to periodically interrupted and redeveloped thermal boundary-layers due to bifurcation. It is also shown that increasing Re leads to thinning of thermal boundary-layers resulting in an enhanced heat transfer in terms of an increased average Nusselt number from 38% to 74%. However, there is an increased pressure drop due to channel shape and obstacle in fluid flow. Further, due to a high pressure drop penalty at high Re, CD shape microchannel with bifurcation loses its heat transfer effectiveness.

Copyright (c) 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In