scholarly journals Analysis of oscillatory flow and heat transfer in an oscillating heat pipe

2010 ◽  
Author(s):  
Wei Shao
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Oscillatory Flow ◽  
Oscillating Heat Pipe ◽  
Flow And Heat Transfer

Experimental Investigation on Nanofluids Effectiveness on Heat Transfer in Oscillating Heat Pipe

2013 ◽  
Vol 856 ◽  
pp. 98-102 ◽  
Author(s):  
Hamid R. Goshayeshi ◽  
Ali Khosravi ◽  
Mehdi Abedpour Karizaki
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
High Speed ◽  
Oscillatory Flow ◽  
Glass Tube ◽  
Heat Pipes ◽  
Oscillating Heat Pipe ◽  
Flow And Heat Transfer ◽  
Heat Loads

An experimental investigation of the oscillatory flow and heat transfer in a vertical oscillating heat pipe (OHP) was conducted. The oscillating heat pipe was made of a copper-glass tube. Flow inside the oscillating heat pipe at different heat loads was recorded by a high speed camera. Through this research, the authors investigated the effect of utilizing nanofluids on heat transfer amount in heat pipes. The employed nanofluids in this study were water-Fe2O3, water-SiO2and water-TiO2with various volumetric concentrations. The results show that after adding nanoparticles in the base fluid (here water) heat transfer rate increases significantly. It's also noteworthy, of the all applied nanofluids, water-TiO2mixture presents the best enhancement in heat transfer amount.

Effect of Internal Wick Structure on Liquid-Vapor Oscillatory Flow and Heat Transfer in an Oscillating Heat Pipe

2009 ◽  
Vol 131 (12) ◽  
Author(s):  
Jiajun Xu ◽  
Yuwen Zhang ◽  
Hongbin Ma
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Oscillatory Flow ◽  
Liquid Slug ◽  
Transfer Coefficients ◽  
Oscillating Heat Pipe ◽  
Evaporation And Condensation ◽  
Flow And Heat Transfer ◽  
Wick Structure ◽  
Liquid Vapor

Liquid-vapor oscillating flow and heat transfer in a vertically placed oscillating heat pipe (OHP) with a sintered particle wick structure are analyzed in this paper. The oscillatory flow of the liquid slug is driven by the variations in pressures in the vapor plug due to evaporation and condensation. The evaporation and condensation heat transfer coefficients are obtained by solving the microfilm evaporation and condensation on the sintered particles. The sensible heat transfer between the liquid slug and the channel wall are obtained by analytical solution or empirical correlations depending on whether the liquid flow is laminar or turbulent. The effects of the sintered particles wick structure on the oscillatory flow, as well as sensible and latent heat transfer, are analyzed and compared with the results without wick structure. A parametric study on the oscillatory flow and heat transfer in the OHP with sintered particle wick structure is also performed.

Effects of Film Evaporation and Condensation on Oscillatory Flow and Heat Transfer in an Oscillating Heat Pipe

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Wei Shao ◽  
Yuwen Zhang
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Pipe ◽  
Liquid Flow ◽  
Oscillatory Flow ◽  
Film Condensation ◽  
Evaporator Temperature ◽  
Oscillating Heat Pipe ◽  
Film Evaporation ◽  
Flow And Heat Transfer

An advanced theoretical model of a U-shaped minichannel, a building block of a closed-end oscillating heat pipe, has been developed. Thin film evaporation in the evaporator and thin film condensation in the condenser, axial variation of surface temperature, and pressure loss at the bend are incorporated in this model. The sensible heat transfer coefficients between the liquid slug and the wall are obtained by analytical solution for laminar liquid flow and by empirical correlations for turbulent liquid flow. The effects of the inner diameter, evaporator temperature on the thermally induced oscillatory flow and heat transfer performance, and the mechanism of film condensation and evaporation are investigated.

Liquid-Vapor Oscillating Flow and Heat Transfer in a U-Shaped Minichannel With Internal Wick Structure

2009 ◽  
Author(s):  
Jiajun Xu ◽  
Yuwen Zhang ◽  
H. B. Ma
Keyword(s):  
Heat Transfer ◽  
Oscillatory Flow ◽  
Oscillating Flow ◽  
Transfer Coefficients ◽  
Oscillating Heat Pipe ◽  
Heat Transfer Coefficients ◽  
Evaporation And Condensation ◽  
Flow And Heat Transfer ◽  
Wick Structure ◽  
Liquid Vapor

Liquid-vapor oscillating flow and heat transfer in a vertically placed oscillating heat pipe (OHP) with a sintered particle wick structure inside are analyzed in this paper. The evaporation and condensation heat transfer coefficients are obtained by solving the microfilm evaporation and condensation on the sintered particles. The sensible heat transfer between the liquid slug and the channel wall are obtained by analytical solution or empirical correlations, depending on whether the liquid flow is laminar or turbulent. The effects of the maximum evaporation and condensation angles on the oscillatory flow, as well as sensible and latent heat transfer are analyzed.

The Phenomenon of Unidirectional Circulating Flow in an Oscillating Heat Pipe

2019 ◽  
Author(s):  
Chunrong Yu ◽  
Yulong Ji ◽  
Lilin Chu ◽  
Zongyu Wang ◽  
Yadong Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Tilt Angle ◽  
Heat Input ◽  
Working Fluid ◽  
Oscillating Heat Pipe ◽  
Flow And Heat Transfer ◽  
The Difference ◽  
High Level ◽  
Relative High Level

Abstract The phenomena of two different types of unidirectional circulating flow pattern in a copper oscillating heat pipe (OHP) were firstly discovered and investigated. The OHP has six turns and three sections: evaporator, condenser and adiabatic sections with lengths of 40 mm, 64 mm, and 51 mm, respectively. R152a was used as the working fluid, the effects of the tilt angle from 0° to 90° and the heat input on the flow and heat transfer of the working fluid in OHP was studied. The experimental results showed that (1) the OHP charged with R152a can form a unidirectional circulating flow at any tilt angle under certain heat input, and the unidirectional circulating flow become steady as the heat input increases; (2) another type of circulating flow was found in the same OHP as the heat input increased to a relative high level, the difference between the two types of circulating flow is that the liquid slugs move forward with or without back forward oscillating movement; (3) the unidirectional circulating flow of the working fluid without back forward oscillating movement in the OHP significantly enhance the heat transfer of OHP.

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