
Accession Number : ADA195223
Title : Experimental and Analytical Study of TwoPhase Flow in Zero Gravity.
Descriptive Note : Final rept. Sep 85Oct 87,
Corporate Author : LEVY (S) INC CAMPBELL CA
Personal Author(s) : Abdollahian, Davood ; Grief, Ralph ; Carey, Van P ; LiPing, Wang
PDF Url : ADA195223
Report Date : Mar 1988
Pagination or Media Count : 147
Abstract : More effective and efficient thermal transport techniques will be needed for heat rejection from equipment on satellites. Circulating twophase fluid loops have been suggested and laboratory tested for possible application in the above areas. In comparison to a singlephase loop, the twophase system operates at considerably smaller flow rates and maintains a tighter temperature control with higher heat transfer coefficients. However, the twophase fluid flow regimes, pressure gradients and heat transfer coefficients must be evaluated for application in the weightless environment of an orbiting satellite. This projecting studies twophase flow behavior under zero gravity conditions. The overall objectives of this study were to generate a data base for twophase pressure drop and the voidquality relationship under simulated zero gravity conditions and to develop analytical models to predict these parameters for bubbly and annular flow. The simulation of zero gravity twophase flow was achieved by using two immiscible liquids with equal densities to eliminate the buoyancy component. Although this approach does not eliminate the gravity effects, it provides a representation for void distribution in the absence of gravity. The modeling effort is limited to developing relations for the twophase friction multiplier and voidquality relation under bubbly and annular flow conditions. The bubbly flow model is based on the assumption of local homogeneous conditions between the phases but allows for void distribution in the radial direction. Separated flow conservation equations are used, and singlephase turbulent flow eddy diffusivity relations are employed.
Descriptors : *THERMAL RADIATION, *TWO PHASE FLOW, *WEIGHTLESSNESS, *HEAT TRANSFER, ANNULAR FLOW, ARTIFICIAL SATELLITES, BUOYANCY, CIRCULATION, CONSERVATION, DATA BASES, DENSITY, EFFICIENCY, ENVIRONMENTS, EQUATIONS, FLOW RATE, FLOW SEPARATION, FLUID FLOW, FLUIDS, GRAVITY, HEAT, HEAT TRANSFER COEFFICIENTS, HOMOGENEITY, LIQUIDS, LOOPS, MATHEMATICAL MODELS, MODELS, ORBITS, PHASE, PRESSURE, PRESSURE GRADIENTS, REDUCTION, REJECTION, SIMULATION, TEMPERATURE CONTROL, TRANSPORT PROPERTIES, EDDIES(FLUID MECHANICS), TURBULENT FLOW
Subject Categories : Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE