Heat Transfer Characteristics of the Closed Thermosyphon

1965 ◽  
Vol 87 (1) ◽  
pp. 30-39 ◽  
Author(s):  
F. J. Bayley ◽  
G. S. H. Lock
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Theoretical Analysis ◽  
Laminar Boundary Layer ◽  
Open System ◽  
Experimental Results ◽  
Controlled Experiments ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

This paper describes a series of closely controlled experiments made to investigate the performance of the closed thermosyphon. All the regimes previously observed in the open system were identified, and suggestions are made concerning the nature of the process by which the heated and cooled regions of the thermosyphon are hydrodynamically coupled together. A theoretical analysis of the laminar boundary layer regime is given and comparisons made with the experimental results.

Evaporation of Single Drops of n-Pentane/n-Hexane Mixtures in Water

1992 ◽  
Vol 114 (4) ◽  
pp. 965-971 ◽  
Author(s):  
H. Shimaoka ◽  
Y. H. Mori
Keyword(s):  
Heat Transfer ◽  
Temperature Difference ◽  
Vapor Bubble ◽  
Experimental Results ◽  
Rise Velocity ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Transfer Characteristics ◽  
Preceding Work ◽  
Liquid Vapor

The evaporation of isolated drops (2.1−3.0 mm diameter) of nonazeotropic n-pentane/n-hexane mixtures in the medium of water was observed under pressures of 0.11−0.46 MPa and temperature differences up to 27 K. The mole fractions of n-pentane, x, in the mixtures were set at 0.9, 0.5, 0.1, and 0, to be completed by the condition x = 1 set in a preceding work (Shimaoka and Mori, 1990). Experimental results are presented in terms of the instantaneous rise velocity of, and an expression of instantaneous heat transfer to, each drop evaporating and thereby transforming into a liquid/vapor two-phase bubble and finally into a vapor bubble. The dependencies of the heat transfer characteristics on the pressure, the temperature difference, and x are discussed.

Study of Heat Transfer Characteristics in the Boundary Layer of a Visco-Elastic Fluid Under Varying Influencing Parameters

2007 ◽  
Author(s):  
P. Anuradha ◽  
S. Krishnambal
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Numerical Study ◽  
Numerical Technique ◽  
Heat Transfer Characteristics ◽  
Elastic Fluid ◽  
Transfer Characteristics ◽  
Dimensional Parameters ◽  
Influencing Parameters ◽  
Sheet Stretching

The heat transfer characteristics of a visco-elastic fluid within the boundary layer formed by the passage of a sheet stretching at a uniform rate through it are studied under varying influencing parameters using a numerical technique. The influence of considering or ignoring elastic deformation in the thermal analysis is studied in the presence of chosen values of non-dimensional parameters like Prandtl number (Pr) and Eckert number (E). Two cases of sheet surface conditions are considered — (i) PST case involving prescribed surface temperature and (ii) PHF case involving prescribed heat flux at the surface. The results of this numerical study are diagrammatically represented with appropriate conclusions drawn on the influence of the above parameters considered in isolation or together. The trend of results is seen to agree well with those of other researchers who used other solution techniques. A judious choice of the above two principal non-dimensional parameters is suggested for application to a cooling process typical of a polymer extrusion industry.

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