Showing papers in "International Journal of Multiphase Flow in 1993"

TL;DR: In this article, a mathematical model for the advancing contact-line motion on a smooth solid surface is proposed, which eliminates the shear-stress singularity of the classical model and describes the fluid motion as rolling.

TL;DR: In this article, a two-phase gas-liquid flow was studied in small diameter (1.6 mm i.d.) horizontal tubes with different contact angles, including pyrex, polyethylene, polyurethane and fluoropolymer resins.

TL;DR: In this paper, the authors measured void fraction, slug bubble velocity, and pressure loss for rectangular ducts with a narrow gap and a large aspect ratio using the neutron radiography technique, and the void fraction was well-correlated by the drift flux model with the existing correlation for the distribution parameter.

TL;DR: In this article, a model of drying of capillary porous media is presented based on a modified form of invasion percolation theory, where the porous medium is conceptualized as a network of pores connected by narrow throats.

TL;DR: In this paper, drop properties during and after secondary breakup in the bag, multimode and shear breakup regimes were observed for shock-wave-initiated disturbances in air at normal temperature and pressure.

TL;DR: In this paper, two-phase air-water flow pattern data are reported at microgravity conditions during a series of parabolic trajectories flown on the NASA KC-135 aircraft.

TL;DR: In this article, a three-layer model for solid-liquid flow in horizontal pipes is proposed and the model predictions exhibit satisfactory agreement with the experimental data and existing correlations, which overcomes the limitations of the two-layer models.

TL;DR: In this paper, a Lagrangian simulation technique of a non-dilute gas-solid suspension flow is presented, based on the introduction of simulated particle-to-particle collisions during the trajectory calculation of a particle, with a probability which is predicted through an iterative process, since it depends on the local concentration and velocities.

TL;DR: In this paper, the authors present a model that is able to calculate the slug length distribution at any desired position along the pipe and it assumes a random distribution at the inlet of the pipe, including the disappearance of the short slugs, as they move downstream.

TL;DR: In this article, it was shown that the stability behavior regarding the amplification rate is actually almost the same for the two analyses for a wide range of liquid viscosities and for various pipe inclinations.

TL;DR: In this article, the effects of bubble size and entrance length on the void distribution in a vertical upward cocurrent air-water two-phase flow were studied systematically based on the measurements of a dual-sensor resistivity probe.

TL;DR: In this paper, a correlation formula which estimates the holdup fraction is introduced and evaluated for all available experimental data and a simple theory is given which is based on the concentric core-annular flow model and leads to a Reynolds number and friction factor which reduce a large body of experimental data onto one curve; with the best results in the high Reynolds number flow regime.

TL;DR: In this paper, three choking initiation mechanisms are identified: type A (accumulative) choking occurs when solids start to accumulate at the bottom of the conveyor as the saturation gas carrying capacity is reached, type B (blower-/standpipe-induced) choking results from instabilities due to gas blower-conveyor or solids feeder-consveyor interactions where there is insufficient pressure or too limited solidsfeed capacity to provide the needed solids flow; and type C (classical) choking corresponds to a transition to severe slugging.

TL;DR: In this paper, experimental data were determined for co-current air-water horizontal flow in a 00935 m id pipe and flow patterns were identified by a combination of visual/video observations, the pressure fluctuation characteristics and a detailed examination of the pressure loss and holdup data.

TL;DR: In this article, the viscous resuspension of an initially settled bed of particles resulting from the application of a laminar shear flow was studied experimentally in a narrow-gap Couette device.

TL;DR: In this article, a flow regime map for the air/water two-phase flow in the Harwell 30 cm dia horizontal pipeline is compiled for slug frequency, length, holdup, translational velocity and pressure gradient.

TL;DR: In this paper, the particle dispersion characteristics in a confined swirling flow with a swirl number of approx. 0.5 were studied in detail by performing measurements using phase-Doppler anemometry (PDA) and numerical predictions.

TL;DR: In this article, a model to predict the mass flow rate has been developed and has been successfully validated, taking into account the persistence of some metastable liquid in the crack and the special flow pattern which appears in such particular geometry.

TL;DR: In this article, the authors present experimental data on the air entrainment process for a plunging liquid jet, including the size distribution of the bubble diameter, void fraction, bubble velocities and turbulent liquid velocity using a fiber optics phase Doppler anemometer system.

TL;DR: In this article, a quasi-one-dimensional, five-equation, homogeneous, nonequilibrium model has been developed and utilized on a microcomputer to calculate the behavior of flowing, initially subcooled, flashing water systems.

TL;DR: In this article, a wall cavity model is described for use in the calculation of nucleation rates and bubble number densities at flashing inception, and subsequently in calculation of the void development downstream of minimum area zones in nozzles.

TL;DR: In this article, a Lagrangian approach is used to simulate particle dispersion in anisotropic turbulent flows and discrete particles are tracked in three dimensions, influenced by the fluid's turbulent velocity fluctuations.

TL;DR: In this paper, a three-dimensional Lagrangian model for the motion of particles in turbulent flows has been established, and the computed results are compared with the experimental data for the particle dispersion, velocity correlations and velocity decay.

TL;DR: In this article, the authors improved the description of slug flow and the closure relations required in mean kinematic slug flow models using local (optical) and cross-sectional (conductance) probes.

TL;DR: In this article, a numerical simulation of the motion of solid particles in a horizontal, two-dimensional, turbulent channel flow is presented, which is based on the Lagrangian approach, which treats the dispersal phase as a number of single particles.

TL;DR: In this article, the growth of capillary ripples on a thin liquid film flowing concurrently with a high velocity gas flow is explored, and a mechanism is examined whereby the ripples receive their energy from pressures and shear stresses exerted at the wave surface by the gas.

TL;DR: In this article, a perturbation solution for small film thickness is developed that predicts two film surface maxima for each cycle of the solid surface, which is very good for small values of the parameter δ, defined as the ratio of the Nusselt film thickness and the amplitude of the wavy solid surface.