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Laminar condensation on a moving drop. Part 1. Singular perturbation technique

Published online by Cambridge University Press:  20 April 2006

J. N. Chung
Affiliation:
Department of Mechanical Engineering, Washington State University, Pullman, WA 99164–2920
P. S. Ayyaswamy
Affiliation:
Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104
S. S. Sadhal
Affiliation:
Department of Mechanical Engineering, University of Southern California, Los Angeles, CA 90089–1453

Abstract

In this paper, laminar condensation on a spherical drop in a forced flow is investigated. The drop experiences a strong, radial, condensation-induced velocity while undergoing slow translation. In view of the high condensation velocity, the flow field, although the drop experiences slow translation, is not in the Stokes-flow regime. The drop environment is assumed to consist of a mixture of saturated steam (condensable) and air (non-condensable). The study has been carried out in two different ways. In Part 1 the continuous phase is treated as quasi-steady and the governing equations for this phase are solved through a singular perturbation technique. The transient heat-up of the drop interior is solved by the series-truncation numerical method. The solution for the total problem is obtained by matching the results for the continuous and dispersed phases. In Part 2 both the phases are treated as fully transient and the entire set of coupled equations are solved by numerical means. Validity of the quasi-steady assumption of Part 1 is discussed. Effects due to the presence of the non-condensable component and of the drop surface temperature on transport processes are discussed in both parts. A significant contribution of the present study is the inclusion of the roles played by both the viscous and the inertial effects in the problem treatment.

Type
Research Article
Copyright
© 1984 Cambridge University Press

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References

Acrivos, A. & Taylor, T. D. 1962 Heat and mass transfer from single spheres in Stokes flow Phys. Fluids 5, 387394.Google Scholar
Chung, J. N. & Ayyaswamy, P. S. 1981a Laminar condensation heat and mass transfer to a moving drop AIChE J. 27, 372377.Google Scholar
Chung, J. N. & Ayyaswamy, P. S. 1981b Material removal associated with condensation on a droplet in motion Intl J. Multiphase Flow 7, 329342.Google Scholar
Chung, J. N., Ayyaswamy, P. S. & Sadhal, S. S. 1984 Laminar condensation on a moving drop. Part 2. Numerical solutions J. Fluid Mech. 139, 131144.Google Scholar
Clift, R., Grace, J. R. & Weber, M. E. 1978 Bubbles, Drops and Particles. Academic.
Dennis, S. C. R., Walker, J. D. A. & Hudson, J. D. 1973 Heat transfer from a sphere at low Reynolds numbers J. Fluid Mech. 60, 273283.Google Scholar
Fendell, F. E., Sprankle, M. L. & Dodson, D. S. 1966 Thin-flame theory for a fuel droplet in slow viscous flow J. Fluid Mech. 26, 267280.Google Scholar
Sadhal, S. S. & Ayyaswamy, P. S. 1983 Flow past a liquid drop with a large non-uniform radial velocity J. Fluid Mech. 133, 6581.Google Scholar
Yang, J. W. 1973 Laminar film condensation on a sphere. Trans. ASME C: J. Heat Transfer 95, 174174.Google Scholar