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Showing papers on "Slug flow published in 1972"



Journal ArticleDOI
Ramani Mani1
TL;DR: In this paper, the total power and power spectrum due to a point source convecting at a uniform subsonic velocity along the axis of a round jet is calculated, where the source is a discrete frequency source in its own frame of reference.

58 citations


Journal ArticleDOI
TL;DR: In this article, the two-phase slug flow regime in horizontal cocurrent gas-liquid flow was studied for the case of the liquid phase containing small amounts of polyacrylamide, a drag-reducing long chain polymer.
Abstract: The two-phase slug flow regime in horizontal cocurrent gas-liquid flow was studied for the case of the liquid phase containing small amounts of polyacrylamide, a drag-reducing long chain polymer. The experimental work was performed in a 2.54 cm I.D. horizontal test section 10.7 m long. Results indicated that two-phase drag reduction was greater than in single phase flow at the same superficial liquid velocities. By the use of pressure drop results with and without polymer additive, and a knowledge of slug geometry, frequency, and velocity, it was possible to separate approximately the contribution to the pressure drop of liquid wall friction and slug intertial effects. In all cases, the acceleration term was important and is the major energy term at most flow conditions. The technique may be of general usefulness in determining accelerational effects in two phase flows. When drag reducing agents have been added to a horizontal slug flow, the pressure loss can be correlated successfully both by the Lockhart-Martinelli type of relationship or by a universal drag reduction curve of the type proposed by Virk.

42 citations



Journal ArticleDOI
TL;DR: In this paper, a basic equation of air-lift pump performance is derived from a simple momentum equation, and frictional pressure drop in two-phase flow is expressed by means of liquid volume fraction of the mixture.
Abstract: A basic equation of air-lift pump performance is derived from a simple momentum equation. In the analysis, frictional pressure drop in two-phase flow is expressed by means of liquid volume fraction of the mixture, and slug flow is assumed in order to obtain the relationship between liquid volume fraction and flow rates of both phases. The results predicted by the analysis are compared with experimental data of other investigators as well as of the authors. Good agreement with experimental data is shown in the ranges of 25 mm≤D (inner diameter)≤100 mm, 4 m≤L (length of pipe)≤42 m and 0.4<σ (submergence ratio)<0.8. To give a clear explanation for pump characteristics, the efficiency of air-lift pump is subdivided into two components, the pipe efficiency and the ideal discharge efficiency. A procedure of a pump design is proposed.

20 citations


Journal ArticleDOI
TL;DR: In this article, the dynamic response of a packed gas absorber to inlet gas composition changes was investigated by the pulse response technique for the case where absorption was accompanied by pseudo first-order irreversible chemical raction.
Abstract: The dynamic response of a packed gas absorber to inlet gas composition changes was investigated by the pulse response technique for the case where absorption was accompanied by pseudo first-order irreversible chemical raction. The solute-carrier-solvent system was carbon dioxide-air-0.07 normal aqueous sodium hydroxide solution. The column used was 6.5 in. I.D. Plexiglass packed to a height of 6.15 ft. with either ¼-in. Raschig rings or ¾-in. Berl Saddles. Gas flow rates ranged from 1.5 to 10 lb.-moles/hr./sq.ft. and liquid flow rates ranged from 0 to 200 lb.-moles/hr./sq.ft. A pulse of carbon dioxide was injected into the inlet air stream and monitored as it entered the packed section. The outlet gas and liquid phase concentrations were continuously monitored as the resulting pulses left the packed section. The pulse response data were reduced to frequency response by digital computer calculations. Reliable data could be obtained over the frequncy range 0 to 5 radians/second. The experimental results were compared with theoretical predictions from the slug flow, axial diffusion, and mixing cell models. Both the mixing cell model and the axial diffusion model satisfactorily predicted the experimental frequency responses over the entire frequency range covered. The slug flow model was found unsatisfactory for predicting gas-phase amplitude ratios at high frequencies, where axial mixing affected the amplitude ratios. Gas-phase particle Peclet numbers and overall mass transfer coefficients based on the gas-phase driving force determined in the present absorption system were in reasonable agreement with the values reported in the literature.

4 citations


Journal ArticleDOI
TL;DR: In this article, the effects of radiation and conduction on the temperature profile and the Nusselt number for slug flow and for the parabolic velocity distribution were investigated. But the results may be interpreted more generally as referring to any infra red radiating diatomic gas.
Abstract: The problem of energy transfer in a thermally developing, radiating and conducting medium is studied. In particular, laminar flow of carbon monoxide is considered although the results may be interpreted more generally as referring to any infra red radiating diatomic gas. The effects of radiation and conduction on the temperature profile and the Nusselt number are presented for slug flow and for the parabolic velocity distribution.

4 citations




Journal ArticleDOI
TL;DR: In this paper, a model of a slug flow holder which may eliminate or greatly reduce the problems caused by types of flow in holding tubes of commercial egg pasteurizers is discussed.
Abstract: Problems caused by types of flow in holding tubes of commercial egg pasteurizers are discussed. A model of a slug flow holder which may eliminate or greatly reduce these problems has been built and tested in the laboratory. It is operated by product flow and maintains a front to each slug from which there is no forward mixing of product with the preceding slug. It works equally well with water or a carboxymethyl-cellulose solution with the same viscosity as salt yolk.

1 citations




Journal ArticleDOI
TL;DR: In this paper, the upper limit of the boundary between fish scale type slug flow and froth flow in a vertical small tube is defined, and the condition of generating the relaxation oscillation is as follows Cc < 1/q%gt; < qgB1/q-q-QgA1/Q/PVA-PVB where Cc:Qg3/(P4-PV)q=constant q: pressure of air chamber Qg2: rate of air flow which streams into tube
Abstract: There is a very distinctly discontinuous region at the boundary between fish scale type slug flow and froth flow in a vertical small tube. This involves a possibility of leading to the relaxation oscillation of a stream, when the air line has an air chamber, and the inlet hole to the chamber has a fairly high degree of resistance. In the case of constant rate of liquid flow, the condition of generating the relaxation oscillation is as follows Cc<1/q%gt;