Showing papers on "Slug flow published in 1978"
TL;DR: In this paper, experimental data for gas holdup in liquid slugs were reported for two different pipe sizes (2.58 cm and 5.12 cm I.D.) and a simple empirical correlation was developed and is shown to be a significant improvement over the only other published correlation proposed by Hubbard (1965).
203 citations
TL;DR: In this paper, a semi-mechanistic model for two phase gas-liquid slug flow was proposed and extended to apply to the entire intermittent flow regime, which requires the use of empirical correlations for the slug velocity and the in situ liquid volume fraction in the slug.
Abstract: A semi-mechanistic model for two phase gas-liquid slug flow proposed recently by Dukler and Hubbard has been modified and extended to apply to the entire intermittent flow regime. Flow predictions of the model proposed in this paper are compared with detailed experimental data recently obtained for an air-oil system.
The model requires the use of empirical correlations for the slug velocity and the in situ liquid volume fraction in the slug.
In addition, either the slug frequencies or length corresponding to the given design conditions must be known. However, calculated values of average pressure gradient and in situ liquid volume fraction are relatively insensitive to these latter parameters, and in fact, good results are obtained assuming a constant slug length.
The paper includes a discussion of the limitations of the proposed model and the expected direction of further study required to extend its mechanistic aspects.
193 citations
TL;DR: In this paper, an entry solution and the subsequent approach to the fully developed configuration are obtained for large Rayleigh number flow in a fracture zone with impermeable walls on which the temperature increases linearly with depth.
Abstract: Faulted regions associated with geothermal areas are assumed to be composed of rock which has been heavily fractured within the fault zone by continuous tectonic activity. The fractured zone is modelled as a vertical, slender, two-dimensional channel of saturated porous material with impermeable walls on which the temperature increases linearly with depth. The development of an isothermal slug flow entering the fault at a large depth is examined. An entry solution and the subsequent approach to the fully developed configuration are obtained for large Rayleigh number flow. The former is characterized by growing thermal boundary layers adjacent to the walls and a slightly accelerated isothermal core flow. Further downstream the development is described by a parabolic system. It is shown that a class of fully developed solutions is not spatially stable.
33 citations
20 citations
TL;DR: In this paper, a rod bundle consisting of four vertical 0.25-in-diam x 24.0in-long rods arranged in a single row with spring collar supports was photographed.
Abstract: Flow patterns that occur in a rod bundle with forced upward flow of boiling water have been photographed. The experimental rod bundle consisted of four vertical 0.25-in.-diam x 24.0-in-long rods arranged in a single row with spring collar supports. The tested conditions were: pressure-400 to 2000 psia, mass velocity-250,000 to 3,000,000 lb/h.ft/sup 2/, and heat flux (uniform)-up to 1,600,000 Btu/h.ft/sup 2/. The observed two-phase flow patterns were bubble flow, froth flow, slug flow, and annular flow. These flow patterns were mapped at constant pressure on plots of mass velocity versus flowing quality.
20 citations
TL;DR: In this paper, an analysis for adsorption from a fluid in Poiseville flow to a very thin coating on the walls of a cylindrical channel is presented, where Axial diffusion is ignored, an infinite rate of the adsorptive reaction is assumed, and the partition ratio is assumed to be very large.
Abstract: An analysis is presented for adsorption from a fluid in Poiseville flow to a very thin coating on the walls of a cylindrical channel. Axial diffusion is ignored, an infinite rate of the adsorption reaction is assumed, and the partition ratio is assumed to be very large. Several nonlinear Langmuir adsorption isotherms are considered. An analytical solution is obtained for an irreversible isotherm, while finite-difference solutions are presented for other isotherms. For the case of a fully developed constant-pattern concentration profile, the breakthrough curves presented are in reasonable agreement with those obtained by assuming slug flow and a constant mass transfer coefficient. The constant mass transfer coefficient for best agreement varies from that obtained with Sherwood numbers of 3.66 to 4.36, depending on the shape of the isotherm.
5 citations
TL;DR: In this paper, three conceptual models for two-phase flow in ducts have been adapted to describe flow in coarse granular media and the best model was chosen based on its agreement with the experimental head drop results.
Abstract: Air may be entrained in the flow in porous shore structure under wave action. Three conceptual models for two-phase flow in ducts have been adapted to describe flow in coarse granular media. These are the homogeneous, bubbly drift-flux, and slug drift-flux models. An experimental study was undertaken to check the three models against air-water flow in three coarse granular porous media. The best model was chosen based on its agreement with the experimental head drop results. On this basis the slug flow drift-flux model is recommended to calculate the effect of entrained air on the hydraulic conductivity for co-current and counter current flows.
4 citations