A study of turbulent heat transfer in convergent-divergent shaped microchannel with ribs and cavities using CFD

  • Pankaj Srivastava Instruments Research and Development Establishment, Defence Research and Development Organisation Dehradun - 248008, Uttarakhand, India.
  • Anupam Dewan Department of Applied Mechanics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi - 110016, India. Phone: +911126594217.
Keywords: Heat transfer enhancement, turbulent heat transfer, thermal resistance, ribs and cavities

Abstract

This paper presents the effects of microchannel shape with ribs and cavities on turbulent heat transfer. Three-dimensional conjugate heat transfer using the SST k-ω turbulence model has been investigated for four different microchannels, namely, rectangular, rectangular with ribs and cavities, convergent-divergent (CD) and convergent-divergent with Ribs and Cavities (CD-RC). The flow field, pressure and temperature distributions and friction factor are analyzed, and thermal resistance and average Nusselt number are compared. The thermal performance of the CD-RC microchannel is found to be better than that of other microchannels considered in terms of an average Nusselt number increased from 16% to 40%. Heat transfer increases due to a strong fluid mixing and periodic interruption of boundary-layer. It is observed that with an increase in Reynolds number (Re), the thermal resitance drops rapidly. The thermal resistance of the CD-RC microchannel is decreased by 30% than that of the rectangular microchannel for Re ranging from 2500 to 7000. However, such design of microchannel loses its heat transfer effectiveness due to a high pumping power at high values of Re.

Published
2020-03-23
How to Cite
Srivastava, P., & Dewan, A. (2020). A study of turbulent heat transfer in convergent-divergent shaped microchannel with ribs and cavities using CFD. Journal of Mechanical Engineering and Sciences, 14(1), 6344 - 6361. https://doi.org/10.15282/jmes.14.1.2020.12.0497
Section
Article