scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
2016 ◽  
Vol 94 ◽  
pp. 422-432 ◽  
Author(s):  
N. Chikhi ◽  
R. Clavier ◽  
J.-P. Laurent ◽  
F. Fichot ◽  
M. Quintard

Author(s):  
Josep Escrig Escrig ◽  
Buddhika Hewakandamby ◽  
Georgios Dimitrakis ◽  
Barry Azzopardi

Intermittent gas and liquid two-phase flow was generated in a 6 m × 67 mm diameter pipe mounted rotatable frame (vertical up to −20°). Air and a 5 mPa s silicone oil at atmospheric pressure were studied. Gas superficial velocities between 0.17 and 2.9 m/s and liquid superficial velocities between 0.023 and 0.47 m/s were employed. These runs were repeated at 7 angles making a total of 420 runs. Cross sectional void fraction time series were measured over 60 seconds for each run using a Wire Mesh Sensor and a twin plane Electrical Capacitance Tomography. The void fraction time series data were analysed in order to extract average void fraction, structure velocities and structure frequencies. Results are presented to illustrate the effect of the angle as well as the phase superficial velocities affect the intermittent flows behaviour. Existing correlations suggested to predict average void fraction and gas structures velocity and frequency in slug flow have been compared with new experimental results for any intermittent flow including: slug, cap bubble and churn. Good agreements have been seen for the gas structure velocity and mean void fraction. On the other hand, no correlation was found to predict the gas structure frequency, especially in vertical and inclined pipes.


2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Renato P. Coutinho ◽  
Paulo J. Waltrich ◽  
Wesley C. Williams ◽  
Parviz Mehdizadeh ◽  
Stuart Scott ◽  
...  

Abstract Liquid-assisted gas-lift (LAGL) is a recently developed concept to unload wells using a gas–liquid fluid mixture. The success deployment of the LAGL technology is related to the behavior of two-phase flow through gas-lift valves. For this reason, this work presents an experimental and numerical study on two-phase flow through orifice gas-lift valves used in liquid-assisted gas-lift unloading. To the knowledge of the authors, there is no investigation in the literature on experimental characterization of two-phase flow through gas-lift valves. Experimental data are presented for methane-water flow through gas-lift valves with different orifice port sizes: 12.7 and 17.5 mm. The experiments were performed for pressures ranging from 1.00 to 9.00 MPa, gas flow rates from 0 to 4.71 m3/h, and water flow rate from 0 to 0.68 m3/min. The experimental results are compared to numerical models published in the literature for two-phase flow through restrictions and to commercial multiphase flow simulators. It is observed that some models developed for two-phase flow through restrictions could successfully characterize two-phase flow thorough gas-lift valves with errors lower than 10%. However, it is first necessary to experimentally determine the discharge coefficient (CD) for each gas-lift valve. The commercial flow simulators showed a similar performance as the models available in the literature.


Author(s):  
W. G. Sim

An approximate analytical model, to predict the two-phase damping for upward cross-flow through horizontal bundles, has been developed. This model will allow researches to provide analytical estimates of the damping ratios. The existing semiempirical approach by Pettigrew and Taylor (2003) was approximated by taking the lower envelope of the damping data. To estimate the void fraction for the cross-flow, the void fraction model proposed by Feenstra etc (2000) is utilized. The development of the present damping model stemmed from the two-phase multiplier of pressure loss and the momentum flux of the two-phase flow. The important variables on the damping are identified. The results of the present model agree well with experimental damping ratios in air-mixtures for a sufficiently wide range of pitch mass ratio, quality and p/d ratios. It has also shown predictive capability for steam-water mixtures and Freon 11.


1988 ◽  
Vol 110 (1) ◽  
pp. 22-28 ◽  
Author(s):  
C. E. Taylor ◽  
M. J. Pettigrew ◽  
F. Axisa ◽  
B. Villard

The fluctuating forces induced by water and air/water cross flow on tube rows with pitch to diameter ratios of 1.5 and 3 were measured. Direct measurement of force spectra was possible because the tube was mounted on force transducers. The tubes within the test section were 300 mm in length and 30 mm in diameter. Results were obtained over ranges of void fraction and mass flux from 0 to 95 percent and 375 to 4125 kg/(m2s), respectively. A reasonably uniform spatial distribution of the void fraction was achieved through the use of an air/water mixing unit. The reported results include the power density spectra of the fluctuating forces and their corresponding force coefficient.


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