Theoretical Study of Laminar Film Condensation On Horizontal Ellipitical Tubes Under Conditions of Free and Forced Convection
Abstract
Analytical studies have been made of laminar film condensation on a horizontal elliptical cylinder in a pure saturated vapor under conditions of free and forced convection. Estimation of interfacial shear stress was made in two ways: the first involving an asymptotic value of the shear stress under conditions of infinite condensation rate and the second based on simultaneously solving the two-phase vapor boundary layer and condensate equations. The latter approach enables the determination of the vapor boundary layer separation point. For the assumption of asymptotic shear stress, effects of surface tension and pressure gradient in the condensate film have been included. At the extremes of eccentricity, corresponding to a circular tube and a vertical plate, the results are compared with theoretical and experimental work of others. Improvement in the condensation heat transfer coefficient was found for elliptical tubes under both free and forced convection conditions when compared to circular tubes of the same surface area. In the latter case, this improvement was due mainly to the reduced drag of the elliptical tube providing a higher vapor velocity for the same pressure drop as that across a circular tube.... Laminar film condensation, Horizontal elliptical tube, Free and forced convection.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1993
- Accession Number
- ADA267161
Entities
People
- Vance H. Adams
Organizations
- Naval Postgraduate School