scholarly journals On the Correlation Equation of Heat Transfer through Condensate Film in the Case of Laminar Film Condensation of Binary Vapor Mixtures.

1991 ◽  
Vol 57 (542) ◽  
pp. 3456-3460
Author(s):  
Tetsu FUJII ◽  
Kan'ei SHINZATO ◽  
Jong Boong LEE
Author(s):  
H Kazeminejad

A simple theory is presented for laminar film condensation of a pure vapour on a vertical rectangular fin which takes account of drag induced on the liquid film by the flow of the condensing vapour. Under these conditions, the governing conjugate differential equations for the fin and condensate flow are solved numerically to determine the fin temperature and condensate film thickness distributions. For the range of parameters investigated, it was found that the reduction in condensate thermal resistance due to vapour shear significantly enhances the heat-transfer rate to the fin and decreases the fin efficiency. The model also provides a clear picture of the relative effect of the gravity force, friction drag and momentum drag on the performance of the fin.


1961 ◽  
Vol 83 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Michael Ming Chen

The boundary-layer equations for laminar film condensation are solved for (a) a single horizontal tube, and (b) a vertical bank of horizontal tubes. For the single-tube case, the inertia effects are included and the vapor is assumed to be stationary outside the vapor boundary layer. Velocity and temperature profiles are obtained for the case μvρv/μρ ≪ 1 and similarity is found to exist exactly near the top stagnation point, and approximately for the most part of the tube. Heat-transfer results computed with these similar profiles are presented and discussed. For the multiple-tube case, the analysis includes the effect of condensation between tubes, which is shown to be partly responsible for the high observed heat-transfer rate for vertical tube banks. The inertia effects are neglected due to the insufficiency of boundary-layer theory in this case. Heat-transfer coefficients are presented and compared with experiments. The theoretical results for both cases are also presented in approximate formulas for ease of application.


2021 ◽  
Author(s):  
Vijay K. Dhir

Abstract In this contribution in honor of Late Prof. E. M. Sparrow, we reflect on the pioneering work of Sparrow and Gregg on the development of similarity solutions for laminar film condensation on a vertical plate. Dhir and Lienhard using this work as a basis developed a generalized solution for isothermal curved surfaces on which gravitational acceleration varied along the surface and for variable gravity situations. Subsequently non-isothermal surfaces were also considered. These studies were publisher earlier in the J. Heat Transfer.


2000 ◽  
Vol 123 (2) ◽  
pp. 294-300 ◽  
Author(s):  
M. Mosaad

The present theoretical study concerns with mixed-convection laminar film condensation outside an inclined elliptical tube with isothermal surface. The assumptions used are as in the classical Nusselt-Rohsenow theory, however, with considering the interfacial vapor shear by extending a circular-tube shear model developed in a previous study. An equivalent diameter, based on equal surface area, is introduced in the analysis to enable comparison with circular tubes. For zero ellipticity, the approach simplifies to the circular tube model developed in our previous work. A numerical solution has been obtained for a wide range of the independent parameters. The results indicate that the heat transfer performance of the inclined elliptical tube enhances with the increase of tube ellipticity compared to an inclined circular tube of equivalent diameter. For forced-convection-dominated film condensation, the rate of this enhancement in the heat transfer coefficient is found smaller than that for pure-free-convection film.


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