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Abstract

In two-phase flow modelling it is desirable to know in each particular flow station along a channel, the fraction of the total area occupied by the vapour phase (void-fraction), and for the same phase the ratio of the mass-flow rate to the total (mass-dryness fraction). In the present paper a phenomenological model is proposed which deals with these terms and takes into account the entrainment of liquid and vapour in the core and in the film region. The capabilities of the model are first tested by carrying out comparisons with velocity measurements in the transverse direction. In general, the velocity profiles from the proposed model are in good agreement with experimental observations of Gill "it et al/". and of Kirillov "it et al/". For the axial pressure gradient the usual force-momentum equation has been employed. The wall shear-stress is calculated from the velocity profile in the film region extended inwards up to the pipe axis. Pressure gradients from the 2nd International Workshop on Two-Phase Flow Fundamentals (Physical Benchmark Exercise) have been successfully represented in vertical and horizontal geometries. For the void-fraction comparisons, the data of Haywood "it et al/". have been used together with the data set of Rooney. Good agreement is obtained even without liquid entrainment in the core region. As a final test of the capabilities of the velocity profile model, the location where the liquid film dries out is calculated in uniformly heated pipes. The predictions are in better agreement than the Bowring correlation.

Additional information

Authors: SKOULOUDIS A N JRC ISPRA ESTAB. PEERLESS S J IMPERIAL COLLEGE OF SCIENCE AND TECHNOLOGY, LONDON (UK) , JRC ISPRA ESTAB.;IMPERIAL COLLEGE OF SCIENCE AND TECHNOLOGY, LONDON (UK)
Bibliographic Reference: 2ND INTERNATIONAL SYMPOSIUM ON TWO-PHASE ANNULAR AND DISPERSED FLOWS, UNIVERSITY OF OXFORD (UK), SEPT. 6-8, 1988, AVAILABILITY: CEC-LUXEMBOURG, DG-XIII-C-3, POB 1907, MENTIONING PAPER EN 34105 ORA
Availability: Can be ordered online
Record Number: 1989126101900 / Last updated on: 1989-06-01
Category: PUBLICATION
Available languages: en
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