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The Stationary Condensation and Radial Outflow of a Liquid Film on a Horizontal DiskThe application of capillary screen liquid acquisition devices to space-based cryogenic propulsion systems is expected to necessitate thermodynamic conditioning in order to stabilize surface tension retention characteristics. The present results have been obtained in the framework of the research of low gravity condensation-flow processes for conditioning cryogenic liquid acquisition devices. The following system is studied: On the top of a subcooled horizontal disk, a liquid film condenses from the ambient saturated vapor. The liquid is forcedly removed at the disk edge, and there is an outward radial flow of the film. Stationary regimes of the flow are uncovered such that (i) the gravity is negligible, being eclipsed by the capillary forces; (ii) the film thickness is everywhere much smaller than the disk radius; and (iii) the slow-flow lubrication approximation is valid. A nonlinear differential equation for the film thickness as a function of the radial coordinate is obtained. The (two-dimensional) fields of velocities, temperature and pressure in the film are explicitly determined by the radial profile of its thickness. The equilibrium is controlled by two parameters: (i) the vapor-disk difference of temperatures and (ii) the liquid exhaust rate. For the flow regimes with a nearly uniform film thickness, the governing equation linearizes, and the film interface is analytically predicted to have a concave-up quartic parabola profile. Thus, perhaps counter-intuitively, the liquid film is thicker at the edge and thinner at the center of the disk.
Document ID
20090014729
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Bolshinskiy, Leonid
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Frenkel, Alexander
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 24, 2013
Publication Date
November 23, 2008
Subject Category
Fluid Mechanics And Thermodynamics
Report/Patent Number
MSFC-2163
Meeting Information
Meeting: 61st Annual Meeting of the APS Division of Fluid Dynamics
Location: San Antonio, TX
Country: United States
Start Date: November 23, 2008
End Date: November 25, 2008
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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