Numerical Study on the Fluid Flow and Heat Transfer Performance of Flat Miniature Heat Pipe for Electronic Devices Cooling

In this paper we reported an advanced structure, the Piranha Pin Fin (PPF), for microchannel flow boiling. Fluid flow and heat transfer performance were evaluated in detail with HFE7000 as working fluid. Surface temperature, pressure drop, heat transfer coefficient and critical heat flux (CHF) were experimentally obtained and discussed. Furthermore, microchannels with different PPF geometrical configurations were investigated. At the same time, tests for different flow conditions were conducted and analyzed. It turned out that microchannel with PPF can realize high-heat flux dissipation with reasonable pressure drop. Both flow conditions and PPF configuration played important roles for both fluid flow and heat transfer performance. This study provided useful reference for further PPF design in microchannel for flow boiling.

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Numerical Study on the Heat Transfer Performance of Non-Newtonian Fluid Flow in a Manifold Microchannel Heat Sink

ECS Meeting Abstracts ◽

10.1149/ma2016-02/36/2298 ◽

2016 ◽

Keyword(s):

Heat Transfer ◽

Fluid Flow ◽

Newtonian Fluid ◽

Heat Sink ◽

Heat Transfer Performance ◽

Numerical Study ◽

Microchannel Heat Sink ◽

Transfer Performance ◽

Manifold Microchannel

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A Numerical Study of the Flow and Heat Transfer in the Pin Fin-Dimple Channels With Various Dimple Depths

Journal of Heat Transfer ◽

10.1115/1.4006098 ◽

2012 ◽

Vol 134 (7) ◽

Cited By ~ 13

Author(s):

Yu Rao ◽

Yamin Xu ◽

Chaoyi Wan

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Convective Heat Transfer ◽

Heat Transfer Performance ◽

Numerical Study ◽

Transfer Performance ◽

Number Range ◽

Flow Friction ◽

Pin Fin ◽

Flow And Heat Transfer

A numerical study was conducted to investigate the effects of dimple depth on the flow and heat transfer characteristics in a pin fin-dimple channel, where dimples are located spanwisely between the pin fins. The study aimed at promoting the understanding of the underlying convective heat transfer mechanisms in the pin fin-dimple channels and improving the cooling design for the gas turbine components. The flow structure, friction factor, and heat transfer performance of the pin fin-dimple channels with various dimple depths have been obtained and compared with each other for the Reynolds number range of 8200–80,800. The study showed that, compared to the pin fin channel, the pin fin-dimple channels have further improved convective heat transfer performance, and the pin fin-dimple channel with deeper dimples shows relatively higher Nusselt number values. The study still showed a dimple depth-dependent flow friction performance for the pin fin-dimple channels compared to the pin fin channel, and the pin fin-dimple channel with shallower dimples shows relatively lower friction factors over the studied Reynolds number range. Furthermore, the computations showed the detailed characteristics in the distribution of the velocity and turbulence level in the flow, which revealed the underlying mechanisms for the heat transfer enhancement and flow friction reduction phenomenon in the pin fin-dimple channels.

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Numerical Modeling of Turbulent Flow and Heat Transfer Within a Bayonet Tube

Volume 8: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A and B ◽

10.1115/imece2007-42520 ◽

2007 ◽

Author(s):

Feng Sun ◽

G.-X. Wang

Keyword(s):

Heat Transfer ◽

Turbulent Flow ◽

Heat Transfer Performance ◽

Numerical Study ◽

Experimental Result ◽

Working Fluid ◽

Transfer Performance ◽

Flow And Heat Transfer ◽

Air Jet ◽

The Impact

This paper presents a numerical study of turbulent flow and heat transfer in a bayonet tube under steady state. First, various turbulent models and wall treatment methods have been tested and validated against the experimental result from a turbulent air jet. The proper combination of turbulent model and wall treatment is then recommended for the turbulent flow within a bayonet tube. The study focuses on the heat transfer performance at the interface of working fluid and the outer tube wall under different Reynolds numbers. Various geometry parameters are considered in this work and the impact of geometry on the heat transfer performance is investigated. Results indicate that the heat transfer at the bottom of the bayonet tube is enhanced compared with that at the straight part. At low Re (< 8000), the maximum Nu occurs at the stagnation point, while the position of the maximum Nu moves away from the stagnant point as Re exceeds 8000. The results are believed to be helpful for the optimized design of a bayonet tube with fully turbulent flows.

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A Numerical Study of the Flow and Heat Transfer Characteristics of Outward Convex Corrugated Tubes With Twisted-Tape Insert

Journal of Heat Transfer ◽

10.1115/1.4031171 ◽

2015 ◽

Vol 138 (2) ◽

Cited By ~ 11

Author(s):

Longbin Yang ◽

Huaizhi Han ◽

Yanjun Li ◽

Xiaoming Li

Keyword(s):

Heat Transfer ◽

Heat Transfer Performance ◽

Swirling Flow ◽

Numerical Study ◽

Twisted Tape ◽

Transfer Performance ◽

Heat Transfer Characteristics ◽

Corrugated Tube ◽

Flow And Heat Transfer ◽

Flow Heat

This work presents a mathematical model for simulating the swirling flow in an outward convex corrugated tube with twisted-tape insert (CT). The synergistic effect on the flow, heat transfer, and friction loss behaviors between the surface-based and fluid-based enhancements is numerically investigated. Renormalized group (RNG) k-ε turbulence model applied in our paper is verified by comparing with experimental results investigated by Manglik and Bergles. Comparisons of the CT and smooth tube with twisted-tape insert (ST) plots are confirmed to investigate the performance differences between them. When comparing the performance of the CT against the ST, the maximum ratio of Nusselt number (Nuc/Nus), ratio of friction factor (f/fs), and overall heat transfer performance (η) values realized in the CT are 1.36, 1.53, and 1.15 times higher, respectively, than the maximum values for those same variables in the ST.

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