Circumferential Variation of Interchange in Horizontal Annular Two-Phase Flow

Abstract

A semi-empirical model can be used to predict the circumferential variation of interchange from the core to the film in the top half of a horizontal gas-liquid pipeline. The model is developed from the equations of motion describing the drop trajectories and is modified by the addition of a constant developed from measurements on an air water system in a 1 -inch pipeline.

Extended Analytical Turbulent Diffusion Model for Particle Dispersion and Deposition in a Horizontal Pipe: Comparison with CFD Simulation

“…c Comparison of analytical and simulated relative concentration as a function of particle weight at the center of the pipe for velocity of 0.1 and 0.5 m/s. d Comparison of analytical and simulated relative concentration as a function of particle weight at the height of y=0.25D from bottom wall for velocity of 0.1 and 0.5 m/s Anderson and Russell [1] and simulated results of Mols and Oliemans [15]. However, the proposed extended analytical model is not capable to simulate cumulative deposition of particles over a certain time period.…”

“…Except for very large particles (>100 μm), for which the motion is totally dominated by gravity and the particle's initial entrainment velocity [1,2,11], there is no theoretical analysis of this deposition flux in a two-dimensional geometry. Anderson and Russell [1] developed a semiempirical expression to correlate deposition and entrainment fluxes, but only for the top half in the tube. The model used to derive this expression assumes that droplet deposition is caused by deterministic drop trajectories intersecting the liquid film.…”

“…None of these studies considered the effect of turbulence as only very large particles were considered. Laurinat et al [13] proposed an empirical fit to a representative deposition flux profile measured by Anderson and Russell [1],…”

“…The main differences between the method used in this paper and the approach of Binder and Hanratty [3] are twofold; (1) in this study, the particle diffusion coefficient and the gravitational settling velocity was assumed to be stationary instead of time-dependent and (2) the inertial and crossing trajectories effects in the particle diffusion coefficient were explicitly included in this study. The first assumption has the great advantage that the one-dimensional problem can then be solved analytically, so that a general expression for the deposition flux independent of the exact quantitative modeling of the particle diffusion coefficient and the gravitational settling velocity can be achieved.…”

Analytical and CFD Investigation of Turbulent Diffusion Model for Particle Dispersion and Deposition

“…Except for very large particles (>100 m), for which the motion is totally dominated by gravity and the particle's initial entrainment velocity [6][7][8] , there is at present no theoretical analysis of this deposition flux in a twodimensional geometry. Anderson and Russell 6 developed a semi-empirical expression to correlate deposition and entrainment fluxes, but only for the top half in the tube. The model used to derive this expression assumes that droplet deposition is caused by deterministic drop trajectories intersecting the liquid film.…”