Heat Transfer Performance of a Novel Microchannel Embedded with Connected Grooves

Ding Yuan,Qingyu Dong,Wei Zhou,Ting Fu

doi:10.1186/s10033-021-00632-w

Abstract

To improve the heat transfer performance of microchannels, a novel microchannel embedded with connected grooves crossing two sidewalls and the bottom surface (type A) was designed. A comparative study of heat transfer was conducted regarding the performances of type A microchannels, microchannels embedded with grooves on their bottom (including types B and C), or on the sidewalls (type D) as well as smooth rectangular microchannels (type E) via a three-dimensional numerical simulation and experimental validation (at Reynolds numbers from 118 to 430). Numerical results suggested that the average Nusselt number of types A, B, C, and D microchannels were 106, 73.4, 50.1, and 12.6% higher than that of type E microchannel, respectively. The smallest synergy angle β and entropy generation number Ns,a were determined for type A microchannels based on field synergy and nondimensional entropy analysis, which indicated that type A exhibited the best heat transfer performance. Numerical flow analysis indicated that connected grooves induced fluid to flow along two different temperature gradients, which contributed to enhanced heat transfer performance.

Highlights

Since Tuckerman et al [1] proposed microchannel heat sinks, the study of microchannels has attracted the attention of many researchers
The present study focused on the effects of connected grooves on fluid flow and heat transfer performance in a microchannel heat sink
The heating copper brick with cartridge heaters inside consisted of an upper rectangular section of 20 mm × 40 mm, which was identical to the backside surface of the microchannel sample

Summary

Introduction

Since Tuckerman et al [1] proposed microchannel heat sinks, the study of microchannels has attracted the attention of many researchers. It is known that fluid in a microchannel is dominated by laminar flow, many scientists and engineers are devoted to improving the heat transfer performance of microchannels. Current enhanced heat transfer technologies for microchannels are classified as either passive or active. Passive technology entails less expense and more convenient fabrication than an active one while achieving desirable heat transfer performance without any extra power consumption except pumping power. Passive technological development mainly includes enhancing the working fluid and improving microchannel structure. Compared to the base fluid, nanofluid has excellent properties such as higher thermal conductivities and significant enhancement of heat transfer performance. This has motivated many researchers to investigate flow and heat transfer performance in microchannel heat sinks with nanofluids. A number of researchers [10,11,12,13,14,15,16] have reported nanofluid

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Results

Conclusion