A Model of 90 Degree Turn Oscillatory Flow and Heat Transfer

2003 ◽  
Author(s):  
Mounir Ibrahim ◽  
Zhiguo Zhang ◽  
Sundeep Kembhavi ◽  
Terrence Simon ◽  
Roy Tew ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Oscillatory Flow ◽  
Flow And Heat Transfer

Performance of a Heat Exchanger Based on Enhanced Heat Diffusion in Fluids by Oscillation: Analysis

1990 ◽  
Vol 112 (1) ◽  
pp. 49-55 ◽  
Author(s):  
M. Kaviany
Keyword(s):  
Heat Transfer ◽  
Boundary Layer Thickness ◽  
Oscillatory Flow ◽  
Heat Diffusion ◽  
Tube Radius ◽  
Flow And Heat Transfer ◽  
Oscillation Analysis ◽  
Different Temperatures ◽  
Fluid Particles

Fluid flow and heat transfer in capillary tubes (Stokes’ boundary-layer thickness nearly equal to the tube radius), subject to oscillatory flow from two reservoirs maintained at different temperatures, has been analyzed. Extension of existing analysis has been made by allowing for finite wall thickness and estimating the viscous dissipation. For a bundle of tubes connected to reservoirs of finite volume, analysis is also made of the oscillatory motion in the reservoirs (assuming a piston-type displacement within the reservoirs). The effects of various fluid and tube parameters on the heat transfer in a single tube are examined. The pathlines followed by fluid particles show that the extent of interaction between the fluid exiting the bundle and the fluid in the reservoirs (or the heat transfer surfaces in the reservoirs) depends strongly on the radial position of the exiting fluid particles. In a follow-up paper, these predictions are compared with some experimental results.

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.

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.

Numerical Investigating of Oscillatory Flow and Heat Transfer Through Stirling Regenerator

2021 ◽  
Author(s):  
Houda Hachem ◽  
Ramla Gheith ◽  
Fethi Aloui
Keyword(s):  
Heat Transfer ◽  
Oscillatory Flow ◽  
Control Volume ◽  
Stirling Engine ◽  
Numerical Code ◽  
Local Thermal Equilibrium ◽  
Flow And Heat Transfer ◽  
The Matrix ◽  
Compression And Expansion ◽  
Regenerator Material

Abstract By developing our proper CFD code under Fortran, the performances of a Stirling engine are studied in unsteady laminar regime and closely linked to the properties of its regenerator. However, it is responsible about the maximum part of losses in the Stirling engine. These losses depend on geometric and physical properties of the material constituting the regenerator. Thus, finding the suitable regenerator material that generates the greatest heat exchange and the lowest pressure drop is a good solution to reduce sources of irreversibility and ameliorate the global performances of the Stirling engine. The aim of this paper is to describe oxillatory flow and heat transfer inside porous regenerator materials and to determine the most suitable regenerator material. Brinkman-Forchheimer-Lapwood extended Darcy model is assumed to simulate momentum transfer within the porous regenerator. And the oscillatory flow is described by the Navier-Stockes compressible equations. The local thermal equilibrium of the gas and the matrix is taken into account for the modelling of the porous regenerator. The governing equations with the appropriate boundary conditions are solved by the control volume based finite element method (CVFEM). A numerical code on the software Fortran is elaborated to evaluate flow and heat transfer characteristics inside regenerator. Results showed that the fluid flow and heat transfer between the compression and expansion phases were varied significantly. It was shown that the superior comprehensive performance of the regenerator makes it possible to improve the performance of Stirling engines.

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.

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