Comparative study of conjugate heat transfer in a single-phase flow in wavy and raccoon microchannels

Abstract

Purpose

This paper aims to emphasize on studying various geometrical modification performed in wavy and raccoon microchannel by manipulating parameters, i.e. waviness (γ), expansion factor (α), wall to fluid thermal conductivity ratio (k_sf), substrate thickness to channel height ratio (d_sf) and Reynolds number (Re) for obtaining optimum parameter(s) that leads to higher heat dissipation rate.

Design/methodology/approach

A three-dimensional solid-fluid conjugate heat transfer numerical model is designed to capture flow characteristics and heat transfer in single-phase laminar flow microchannels. The governing equations are solved using finite volume method.

Findings

The results are presented in terms of average base temperature, average Nusselt number, pressure drop, dimensionless local heat flux, dimensionless wall and bulk fluid temperature, local Nusselt number and performance factor including axial conduction number. Heat dissipation rate with raccoon microchannel configuration is found to be higher compared to straight and wavy microchannel. With waviness of γ = 0.167, and 0.267 in wavy and raccoon microchannel, respectively, performance factor attains maximum value compared to other waviness for all values of Reynolds number. It is also found that the effect of axial wall conduction in wavy and raccoon microchannel is negligible. Additionally, thermal performance of wavy and raccoon microchannel is compared with straight microchannel.

Practical implications

In recent past years, much complex design of microchannel has been proposed for heat transfer enhancement, but the feasibility of available manufacturing techniques to fabricate complex geometries is still questionable. However, fabrication of wavy and raccoon microchannel is easy, and their heat dissipation capability is higher.

Originality/value

This makes the difference in wall and bulk fluid temperature smaller. Thus, present work highlighted the dominance of axial wall conduction on thermal and hydrodynamic performance of wavy and raccoon microchannel under conjugate heat transfer situation.

Citation

Tiwari, N. and Moharana, M.K. (2020), "Comparative study of conjugate heat transfer in a single-phase flow in wavy and raccoon microchannels", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 30 No. 7, pp. 3791-3825. https://doi.org/10.1108/HFF-05-2019-0439