On the nonequilibrium segregation state of a two-phase mixture in a porous column

118 ANNUAL LITERATURE SURVEY 1996 Thermoelastohydrodynamic analysis of a powder slurry containing a mixture of MoS2 particles and a carrier fluid is presented for a line-contact configuration. The constitutive equation of the slurry is a non-Newtonian formulation based on experimental data. The model includes provisions for elastic/plastic deformation of particles in the slurry. Through this deformation, particles are shown to contribute to the load-carrying capacity. (from Authors) Elastohydrodynamic model of the rotary llp seal Salant R.F., Transactions - ASME: Journal of Tribology, 1996, 118/2 (292-296). In English. A model of the non-leaking equilibrium behavior of the lip seal has been developed. It consists of an elastohydrodynamie model of the lubricating film and a simplified model of the meniscus on the air-side of the seal. The model predicts the location of the meniscus, the film thickness and pressure distributions, and the locations of cavitation regions. It also predicts the maximum pressure that can be sealed with zero leakage, and the maximum speed, above which the meuiseus is ingested into the sealing zone. (Author) On the dynamic thermal state in a hydrodynamic bearing with a whirling journal using CFD techniques Tucker P.G. & Keogh P.S., Transactions - ASME: Journal o f Tribology, 1996, 118/2 (356-363). In English. A thermohydrodynamic analysis, based on computational fluid dynamics (CFD) techniques, that accounts for conduction in the rotating and orbating shaft of a hydrodynamic bearing is presented. Dynamic cavitation effects are also introduced, such that pressures in the cavitation region are predicted rather than set. The model predictions are validated against analytical and published experimental results.For the ease of a centrally located synchronous forward circularwhirl orbit,it is demonstrated that the journal does not behave as a circumferentiallyisothermal element and that significantsteady temperature differentialsacross the journal m a y occur. (from Authors) Dimensional analysis of pore scale and field scale immlRcible displacement Hilfer R. & Oren P.E., Transport in Porous Media, 1996, 22/1 (53-72). In English. A basic re-examination of the traditional dimensional analysis of microscopic and macroscopic multiphase flow equations in porous media is presented. We introduce a 'macroscopic capillary number' Ca which differs from the usual microscopic capillary number Ca in that it depends on length scale, type of porous medium and saturation history. Illustrative sample calculations are presented which show that the breakpoint in capillary desaturation curves for different porous media appears to occur at Ca approx 1. The length scale related difference between the macroscopic capillary number Ca for core floods and reservoir floods provides a possible explanation for the systematic difference between residual oil saturations measured in field floods as compared to laboratory experiment. (from Authors) On the nonequilibrium segregation state of a two-phase mixture in a porous column Shapiro A.A. & Stcnby E.H., Transport in Porous Media, 1996, 23/1 (83-106). In English. The problem of segregation of a two-phase multicomponent mixture under the action of thermal gradient, gravity and capillary forces is studied with respect to component distribution in a thick oil-gas condensate reservoir. Governing equations are derived on the basis of nonequilibrium thermodynamics. A steady state of the two-phase mixture with nonzero diffusion fluxes and exchange between phases is described. In the case of binary mixtures analytical formulae for saturation, component distribution and flow in the two-phase zone are obtained. (Authors) Dimensional analysis of pore scale and field scale immiscible displacement Hilfer R. & Oren P.E., Transport in Porous Media, 1996, 22/1 (53-72). In English. A basic re-examination of the traditional dimensional analysis of microscopic and macroscopic multiphasc flow equations in porous media is presented. We introduce a 'macroscopic capillary number' Ca which differs from the usual microscopic capillary number Ca in that it depends on length scale, type of porous medium and saturation history. Illustrative sample calculations are presented which show that the breakpoint in capillary dcsaturation curves for different porous media appears to occur at Ca approx 1. The length scale related difference between the macroscopic capillary number Ca for core floods and reservoir floods provides a possible explanation for the systematic difference between residual oil saturations measured in field floods as compared to laboratory experiment. (from Authors) On the nonequilibrinm segregation state of a two-phase mixture in a porous coinum Shapiro A.A. & Stenby E.H., Transport in Porous Media, 1996, 23/1 (83-106). In English. The problem of segregation of a two-phase multicomponent mixture under the action of thermal gradient, gravity and capillary forces is studied with respect to component distribution in a thick oil-gas condensate reservoir. Governing equations are derived on the basis of nonequilibrium thermodynamics. A steady state of the two-phase mixture with nonzero diffusionfluxesand exchange between phases isdescribed. In the case of binary mixtures analyticalformulae for saturation,component distributionand flow in the two-phase zone are obtained. (Authors) Simulation of Immiscible multiphase flow in porous media: a focus on the capillary fringe of oil-contaminated aquifers Hadad A., Bensabat J. & Rubin H., Transport in Porous Media, 1996, 22/3 (245-269). In English. This paper deals with the analysis of some aspects of the vertical and lateral migration of oil spills in the unsaturated and the capillary zone ofa phreatic aquifer. Motivation stems from the fact that such contamination represents a severe danger for groundwater resources all over the world and from the present acute problem o f jet-fuel contamination in some locations of Israel. The study focuses on the analysis of the upper layers of the aquifer which are subjected to the most significant oil contamination. Neglecting coupled processes and