Hydrodynamics Study of Oil–Water Flow in Coiled Flow Inverter

2020 ◽  
Vol 12 (2) ◽  
pp. 173-180
Author(s):  
Anshumaan Dey ◽  
Monisha M. Mandal

The present numerical study is an effort to examine the hydrodynamics characteristics of two immiscible liquids (oil and water) flowing in different tubes. i.e., straight, coiled and Coiled Flow Inverter (CFI) tube of equal dimensions. CFI is a novel device in which fluid flow inversion takes place at uniform interval length of tube. The effect of oil-water viscosity ratio (µoil/µwater = 1.6 and 30) on velocity contours, phase distribution and pressure drop in the different tubes were investigated. The present work show that flow pattern of oil–water flows was changed from stratified to annular flows at higher water volume fraction for µoil/µwater = 1.6 in CFI. Phase inversion of oil–water flow was observed in CFI at higher viscosity ratio (µoil/µwater = 30). There was remarkable reduction in pressure drop with the increment in volume fraction of water flowing in coiled as well as CFI. CFI being more compact can be efficiently used in industries as chemical reactor, heat exchanger, mixer, etc.

Author(s):  
Elionora A. Caldera ◽  
Miguel Asuaje

In recent years, the oil sector has been struggling with the amount of water produced associated with the total volume of oil production. This quantity is known as water cut and could be over 90% in oil extraction. Handling of this water generates additional costs, affecting the sector’s revenues. In order to solve this problem, several techniques to reduce water cut in the wellbore have been applied. This paper evaluates CFD (computational fluid dynamics) models to predict phase segregation in dispersed oil in water flows. This evaluation has been conducted in an attempt to use CFD models to improve the design methodology of an inline separator of oil-water flow for petroleum production systems [1]. In this 3D study, three cases simulating water dominated dispersed oil-water flow in an inclined pipe 45° from horizontal, were evaluated numerically using a CFD model The oil was considered as the disperse phase and the water as the continuous phase, using Ansys®CFX. Mono size droplet dispersion was employed to represent the dispersed phase. The equations for the forces considered in this study are: drag and buoyancy. The simulated results are compared with the experimental data, which includes water volume fraction, drop pressure and separation efficiency. The result shows an improvement of over 50% in the experimental values, which match the values of the total flow rate (Q), water holdup (Hw) and pressure drop (ΔP), deviating by less than 4%.


2020 ◽  
Vol 15 (1) ◽  
pp. 1-7
Author(s):  
A. Abubakar

The need to ensure qualitative and reliable measurement of pressure drop of the oil-water flow cannot be over emphasized. In this regard, this study focused on the investigation of uncertainty in the measurement of pressure drop of oil-water flow in different acrylic pipe inclinations (0, +5ᴼ, +10ᴼ and -5ᴼ) and diameters (30.6-, 55.7- and 74.7-mm ID). The working fluids were tap water and mineral-based hydraulic oil (Shell Tellus S2 V 15), with medium viscosity and density of 24 cP and 872 kgm-3 respectively while the interfacial tension between the water and the oil was 12.9 mN/m at 25 ᴼC. The selected flow conditions were 0.5 and 1.0 m/s mixture velocities each at 0.1, 0.5 and 0.9 input water volume fractions. The repeatability, accuracy of the pressure transmitter, flow rate of the oil-water mixture and holdup (particularly for the inclined flow) were the sources of errors in the measurement of the pressure drop. The results showed that the average relative uncertainties in the pressure drop in 30.6-mm ID pipe were ±4.6 %, ±10.8 %, ±11.2 % and ±10.8 % in the 0ᴼ, +5ᴼ, +10ᴼ and -5ᴼ inclined flows respectively. Similarly, the average relative uncertainties in the pressure drop in the horizontal 55.7-mm and 74.7-mm ID pipes were ±5.7 % and ±7.5 % respectively. The largest contribution to the uncertainty in the pressure drop came from the flow rate and water holdup in the horizontal and inclined pipes respectively. The least contribution in both  horizontal and inclined pipes came from the accuracy of the pressure transmitter. Key words: Oil-water flow; Pressure drops; Standard uncertainty, Combined standard uncertainty; Expanded uncertainty


Author(s):  
Mohamed H Mansour ◽  
Ali A Zahran ◽  
Lotfy H Rabie ◽  
Ibrahim M Shabaka

The horizontal bubbly two-phase flow is preferably used in various industrial applications because it provides high interfacial areas which enhance the heat and mass transfer. In the present research, the phase distribution of controlled air-water flow in a horizontal acrylic round pipe with 60 mm inside diameter (D) has been investigated experimentally and modeled numerically. The modeled differential pressure and the mixture velocity profile at a distance of 33D from the mixing section (fully developed region) are computed numerically and compared with those obtained experimentally from the two-phase flow system established and maintained at the National Institute of Standards (NIS-Egypt). Furthermore, the numerical and the experimental data have been compared with previous correlations and models. Reasonable quantitative agreement between all data is found. An electronic device based on Arduino Uno board was designed and used with careful data manipulation for measuring the slug bubble velocity. The results point out that the air volume fraction has a maximum value at the upper pipe wall as the gas bubbles tend to migrate to the upper wall. A new correlation was obtained for bubble migration length to the upper pipe wall which is very important in chemical industrial processes and other engineering application.


2021 ◽  
Vol 229 ◽  
pp. 116097
Author(s):  
Jing Shi ◽  
Mustapha Gourma ◽  
Hoi Yeung

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Weiwei E. ◽  
Kevin Pope ◽  
Xili Duan

Abstract In this paper, a new correlation is developed to predict liquid/liquid separation dynamics with a focus on a water/oil mixture. The correlation employs a force balance on the droplets to predict the rising velocity of the oil phase. The effect of droplet coalescence on the droplet's rising velocity is investigated, and the new correlation predicts the coalescence rate based on the oil/water volume fraction, as well as the initial droplet diameter. To develop the correlation for droplet coalescence, a series of new numerical simulations of a batch oil/water separation process were conducted. An equivalent experiment was conducted, the results of which agree well with the numerical predictions (relative error of 13.39%). The new correlation can predict the rate of separation with a relative error of 6.35% compared to numerical predictions.


2019 ◽  
Vol 141 (11) ◽  
Author(s):  
D. S. Santos ◽  
P. M. Faia ◽  
F. A. P. Garcia ◽  
M. G. Rasteiro

The flow of oil/water mixtures in a pipe can occur under different flow patterns. Additionally, being able to predict adequately pressure drop in such systems is of relevant importance to adequately design the conveying system. In this work, an experimental and numerical study of the fully dispersed flow regime of an oil/water mixture (liquid paraffin and water) in a horizontal pipe, with concentrations of the oil of 0.01, 0.13, and 0.22 v/v were developed. Experimentally, the values of pressure drop, flow photographs, and radial volumetric concentrations of the oil in the vertical diameter of the pipe cross section were collected. In addition, normalized conductivity values were obtained, in this case, for a cross section of the pipe where an electrical impedance tomography (EIT) ring was installed. Numerical studies were carried out in the comsolmultiphysics platform, using the Euler–Euler approach, coupled with the k–ε turbulence model. In the simulations, two equations for the calculation of the drag coefficient, Schiller–Neumann and Haider–Levenspiel, and three equations for mixture viscosity, Guth and Simba (1936), Brinkman (1952), and Pal (2000), were studied. The simulated data were validated with the experimental results of the pressure drop, good results having been obtained. The best fit occurred for the simulations that used the Schiller–Neumann equation for the calculation of the drag coefficient and the Pal (2000) equation for the mixture viscosity.


2018 ◽  
Vol 43 (11) ◽  
pp. 6355-6374
Author(s):  
Mujahid O. Elobeid ◽  
Aftab Ahmad ◽  
Abdelsalam Al-Sarkhi ◽  
Luai M. Alhems ◽  
Syed M. Shaahid ◽  
...  

Author(s):  
Parisa Vaziee ◽  
Omid Abouali

Effectiveness of the microchannel heat sink cooled by nanofluids with various particle volume fractions is investigated numerically using the latest theoretical models for conductivity and viscosity of the nanofluids. Both laminar and turbulent flows are considered in this research. The model of conductivity used in this research accounts for the fundamental role of Brownian motion of the nanoparticles which is in good agreement with the experimental data. The changes in viscosity of the nanofluid due to temperature variation are considered also. Final results are compared with the experimental measurements for heat transfer coefficient and pressure drop in microchannel. Enhancement in heat transfer is achieved for laminar flow with increasing of volume fraction of Al2O3 nanoparticles. But for turbulent flow an enhancement of heat removal was not seen and using higher volume fractions of nanoparticles increases the maximum substrate temperature. Pressure drop is increased with using nanofluids because of the augmentation in the viscosity and this increase is more noticeable in higher Reynolds numbers.


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