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Entropy Generation of Free Convection Film Condensation From Downward Flowing Vapors onto a Cylinder or Sphere

  • S. C. Dung (a1), S. H. Tzeng (a1) and S. A. Yang (a1)

Abstract

This study aims at analyzing entropy generation rate of saturated vapor flowing slowly onto and condensed on an isothermal sphere/horizontal cylinder. We derive an expression for entropy generation, which accounts for the resultant action of specified irreversibilities of film-wise condensation outside a cylinder/sphere. The result shows that local entropy generation rate increases with Brinkman group parameters. As Rayleigh group parameters increase, dimensionless heat transfer coefficient is enhanced, but entropy generation number is augmented too. Heat transfer irreversibility dominates over the film flow friction irreversibility in the upper half of a sphere, and vice versa for the lower half of a sphere. As for a cylinder, heat transfer irreversibility dominates over film flow friction irreversibility except around the middle way of streamwise length for the cases of Brinkman group parameters Br / ψ≥ 0.75.

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1.Nusselt, W.“Die Oberflachen Kondenastion des Wasserdamfes,” Zeitschrift des Vereines Deutscher Ingenieure, 60, pp. 541546, pp. 569–575 (1916).
2.Rohsenow, W. M., “Heat Transfer and Temperature Distribution in Laminar Film Condensation,” Trans. ASME, 78, pp. 16451648 (1956).
3.Yang, W. J., “Laminar Film Condensation on a Sphere,” Journal of Heat Transfer 95c, pp. 174178 (1973)
4.Dhir, V. K. and Lienhard, J. H., “Laminar Film Condensation on Plane and Axisymmetric Bodies in Non-Uniform Gravity,” J. Heat Transfer 93c, pp. 97100 (1971).
5.Yang, S. A. and Chen, C. K., “Effects of Surface Tension and Non-Isothermal wall Temperature Variation Upon Filmwise Condensation on Vertical Ellipsoids/Sphere,” Pro. Royal Soc. London A, 442, pp. 301312(1993).
6.Chen, M. M., “An Analytical Study of Laminar Film Condensation: Part 2- Single and Multiple Horizontal Tubes,” Trans. ASME, J. Heat Transfer 83, pp. 5560 (1961).
7.Sparrow, E. M. and Gregg, J. L.“Laminar Condensation Heat Transfer on a Horizontal Cylinder,” Trans. ASME, J. Heat Transfer 81, pp. 291295 (1959).
8.Yang, S. A. and Chen, C. K., “Role of Surface Tension and Ellipticity in Laminar Film Condensation on a Horizontal Elliptical Tube,” Int. J. Heat and Mass Transfer 36, pp. 31353141 (1993).
9.Bejan, A., Entropy Generation Minimization, chapter 4, CRC Press, Boca Raton, FL (1996).
10.Nag, P. K. and Mukherjee, P., “Thermodynamic Optimization of Convective Heat Transfer Though a Duct With Constant Wall Temperature,” Int. J. Heat Mass Transfer, 30, pp. 401405 (1987).
11.Sahin, A. Z., “Second Law Analysis of Laminar Viscous Flow through a Duct Subjected to Constant Wall Temperature,” J. Heat Transfer, 120, pp. 7683 (1998).
12.Saouli, S. and Aiboud-Saouli, S., “Second Law Analysis of Laminar Falling Liquid Film along an Inclined Heated Plate,” Int. Comm. Heat Mass Transfer, 31, pp. 879886 (2004).
13.Adeyinka, O. B. and Naterer, G. F., “Optimization Correlation for Entropy Production and Energy Availability in Film Condensation,” Int. Comm. Heat Mass Transfer, 31, pp. 513524 (2004).
14.Lin, W. W. and Lee, D. J., “Second-Law Analysis of Vapor Condensation of FC-22 in Film Flows Within Horizontal Tubes,” J. Chin. Inst. Chem. Engrs. 32, pp. 8994 (2001).
15.Zhou, Y. Q. and Rose, J. W., “Effect of Two-Dimensional Conduction in the Condensate Film on Laminar Film Condensation on a Horizontal Tube with Variable Wall Temperature,” Int. J. Heat Mass Transfer Volume: 39, Issue: 15, October, pp. 31873191 ( 1996).

Keywords

Entropy Generation of Free Convection Film Condensation From Downward Flowing Vapors onto a Cylinder or Sphere

  • S. C. Dung (a1), S. H. Tzeng (a1) and S. A. Yang (a1)

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