scholarly journals Two-phase fluid flow in geometric packing

2015 ◽  
Vol 373 (2056) ◽  
pp. 20150111 ◽  
Author(s):  
Aureliano Sancho S. Paiva ◽  
Rafael S. Oliveira ◽  
Roberto F. S. Andrade
Keyword(s):  
Viscous Fluid ◽  
Volume Fraction ◽  
Equations Of Motion ◽  
Two Phase ◽  
Ansys Fluent ◽  
Injection Speed ◽  
Complex Dependence ◽  
Complete Set ◽  
High Viscous Fluid ◽  
Phase Fluid

We investigate how a plug of obstacles inside a two-dimensional channel affects the drainage of high viscous fluid (oil) when the channel is invaded by a less viscous fluid (water). The plug consists of an Apollonian packing with, at most, 17 circles of different sizes, which is intended to model an inhomogeneous porous region. The work aims to quantify the amount of retained oil in the region where the flow is influenced by the packing. The investigation, carried out with the help of the computational fluid dynamics package ANSYS-FLUENT , is based on the integration of the complete set of equations of motion. The study considers the effect of both the injection speed and the number and size of obstacles, which directly affects the porosity of the system. The results indicate a complex dependence in the fraction of retained oil on the velocity and geometric parameters. The regions where the oil remains trapped is very sensitive to the number of circles and their size, which influence in different ways the porosity of the system. Nevertheless, at low values of Reynolds and capillary numbers Re <4 and n c ≃10 −5 , the overall expected result that the volume fraction of oil retained decreases with increasing porosity is recovered. A direct relationship between the injection speed and the fraction of oil is also obtained.

scholarly journals Computational fluid simulation of non-Newtonian two-phase fluid flow through a channel with a cavity

2020 ◽  
Vol 24 (2 Part B) ◽  
pp. 1045-1054 ◽  
Author(s):  
Mehdi Ahmadi ◽  
Farsani Khosravi
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Volume Fraction ◽  
Staggered Grid ◽  
Mixed Solution ◽  
Two Phase ◽  
Flow Through ◽  
Velocity Pressure ◽  
Phase Fluid

In this paper, the numerical solution of non-Newtonian two-phase fluid-flow through a channel with a cavity was studied. Carreau-Yasuda non-Newtonian model which represents well the dependence of stress on shear rate was used and the effect of n index of the model and the effect of input Reynolds on the attribution of flow were considered. Governing equations were discretized using the finite volume method on staggered grid and the form of allocating flow parameters on staggered grid is based on marker and cell method. The QUICK scheme is employed for the convection terms in the momentum equations, also the convection term is discretized by using the hybrid upwind-central scheme. In order to increase the accuracy of making discrete, second order Van Leer accuracy method was used. For mixed solution of velocity-pressure field SIMPLEC algorithm was used and for pressure correction equation iteratively line-by-line TDMA solution procedure and the strongly implicit procedure was used. As the results show, by increasing Reynolds number, the time of sweeping the non-Newtonian fluid inside the cavity decreases, the velocity of Newtonian fluid increases and the pressure decreases. In the second section, by increasing n index, the velocity increases and the volume fraction of non-Newtonian fluid after cavity increases and by increasing velocity, the pressure decreases. Also changes in the velocity, pressure and volume fraction of fluids inside the channel and cavity are more sensible to changing the Reynolds number instead of changing n index.

The Effect of Shape Factor on the Magnetic Targeting in the Permeable Microvessel With Two-Phase Casson Fluid Model

2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Sachin Shaw ◽  
P. V. S. N. Murthy
Keyword(s):  
Magnetic Field ◽  
Volume Fraction ◽  
Fluid Model ◽  
Casson Fluid ◽  
Magnetic Drug Targeting ◽  
Magnetic Targeting ◽  
Two Phase ◽  
Coupled Equations ◽  
Casson Fluid Model ◽  
Phase Fluid

The present investigation deals with magnetic drug targeting in a microvessel of radius 5 μm using two-phase fluid model. The microvessel is divided into the endothelial glycocalyx layer wherein the blood obeys Newtonian character and a core region wherein the blood obeys the non-Newtonian Casson fluid character. The carrier particles, bound with nanoparticles and drug molecules, are injected into the vascular system upstream from the malignant tissue and are captured at the tumor site using a local applied magnetic field near the tumor position. Brinkman model is used to characterize the permeable nature of the inner wall of the microvessel. The expressions for the fluidic force for the carrier particle traversing in the two-phase fluid in the microvessel and the magnetic force due to the external magnetic field are obtained. Several factors that influence the magnetic targeting of the carrier particles in the microvasculature, such as the size and shape of the carrier particle, the volume fraction of embedded magnetic nanoparticles, and the distance of separation of the magnet from the axis of the microvessel, are considered in the present problem. The system of coupled equations is solved to obtain the trajectories of the carrier particle in the noninvasive case.

scholarly journals COMPONENTS AND PHASES: MODELLING PROGRESSIVE HYDROTHERMAL ERUPTIONS

2009 ◽  
Vol 50 (3) ◽  
pp. 365-380 ◽  
Author(s):  
ROBERT MCKIBBIN ◽  
THOMASIN A. SMITH ◽  
LUKE FULLARD
Keyword(s):  
Gas Phase ◽  
High Speed ◽  
Equations Of Motion ◽  
Ground Surface ◽  
Continuum Approximation ◽  
Field Observations ◽  
Porous Rock ◽  
Two Phase ◽  
Site Field ◽  
Phase Fluid

AbstractThis is a review of progress made since [R. McKibbin, “An attempt at modelling hydrothermal eruptions”, Proc. 11th New Zealand Geothermal Workshop 1989 (University of Auckland, 1989), 267–273] began development of a mathematical model for progressive hydrothermal eruptions (as distinct from “blasts”). Early work concentrated on modelling the underground process, while lately some attempts have been made to model the eruption jet and the flight and deposit of ejected material. Conceptually, the model is that of a boiling and expanding two-phase fluid rising through porous rock near the ground surface, with a vertical high-speed jet, dominated volumetrically by the gas phase, ejecting rock particles that are then deposited on the ground near the eruption site. Field observations of eruptions in progress and experimental results from a laboratory-sized model have confirmed the conceptual model. The quantitative models for all parts of the process are based on the fundamental conservation equations of motion and thermodynamics, using a continuum approximation for each of the components.

scholarly journals Study on Two-Phase Fluid-Solid Coupling Characteristics in Local-Saturated Zone of Subgrade Considering the Effect of Fine Particles Migration

2020 ◽  
Author(s):  
Yu Ding ◽  
Jia-sheng Zhang ◽  
Yu Jia ◽  
Xiao-bin Chen ◽  
Xuan Wang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Fine Particles ◽  
Volume Fraction ◽  
Solid Skeleton ◽  
Saturated Zone ◽  
Two Phase ◽  
Maximum Value ◽  
Fluid Seepage ◽  
Seepage Characteristics ◽  
Phase Fluid

The fluid seepage in local-saturated zone of subgrade promotes the migration of fine particles in the filler, resulting in the change of pore structure and morphology of the filler and the deformation of solid skeleton, which affects the fluid seepage characteristics. Repeatedly, the muddy interlayer, mud pumping and other diseases are finally formed. Based on the theory of two-phase seepage, the theory of porous media seepage, and the principle of effective stress in porous media, a two-phase fluid-solid coupling mathematical model in local-saturated zone of subgrade considering the effect of fine particles migration is established. The mathematical model is numerically calculated with the software COMSOL Multiphysics○R, the two-phase seepage characteristics and the deformation characteristics of the solid skeleton in local-saturated zone of the subgrade are studied. The research results show that due to the continuous erosion and migration of fine particles in local-saturated zone of the subgrade, the volume fraction of fine particles first increases then decreases and finally becomes stable with the increase of time. And the volume fraction of fine particles for the upper part of the subgrade is larger than that for the lower part of the subgrade. The porosity, the velocity of fluid, the velocity of fine particles, and the permeability show a trend of increasing first and then stabilizing with time; the pore water pressure has no significant changes with time. The vertical displacement increase first and then decrease slightly with the increase of time, and finally tend to be stable. For a filler with a larger initial volume fraction of fine particles, the maximum value of the volume fraction of fine particles caused by fluid seepage is larger, and the time required to reach the maximum value is shorter. It can be concluded that in actual engineering, the volume fraction of fine particles in the subgrade filler should be minimized on the premise that the filler gradation meets the requirements of the specification.

Gas Phase Distribution Effects on Heat Transfer in Upward Vertical Bubbly Channel Flows

2016 ◽  
Author(s):  
Haden Hinkle ◽  
Deify Law
Keyword(s):  
Heat Transfer ◽  
Gas Phase ◽  
Bubble Size ◽  
Single Phase ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Vertical Channel ◽  
Channel Flows ◽  
Two Phase ◽  
Ansys Fluent

Two-phase (non-boiling) flows have been shown to increase heat transfer in channel flows as compared with single-phase flows. The present work explores the effects of gas phase distribution such as volume fraction and bubble size on the heat transfer in upward vertical channel flows. A two-dimensional (2D) channel flow of 10 cm wide by 100 cm high is studied numerically. Numerical simulations are performed using the commercial computational fluid dynamics (CFD) code ANSYS FLUENT. The bubble size is characterized by the Eötvös number. The volume fraction and the Eötvö number are varied parametrically to investigate their effects on Nusselt number of the two-phase flows. All simulations are compared with a single-phase flow condition.

scholarly journals Study on Two-Phase Fluid-Solid Coupling Characteristics in Saturated Zone of Subgrade Considering the Effects of Fine Particles Migration

2020 ◽  
Vol 10 (21) ◽  
pp. 7539
Author(s):  
Yu Ding ◽  
Jia-sheng Zhang ◽  
Yu Jia ◽  
Xiao-bin Chen ◽  
Xuan Wang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Fine Particles ◽  
Volume Fraction ◽  
Solid Skeleton ◽  
Saturated Zone ◽  
Two Phase ◽  
Maximum Value ◽  
Fluid Seepage ◽  
Seepage Characteristics ◽  
Phase Fluid

The fluid seepage in saturated zone of subgrade promotes the migration of fine particles in the filler, resulting in the change of pore structure and morphology of the filler and the deformation of solid skeleton, which affects the fluid seepage characteristics. Repeatedly, the muddy interlayer, mud pumping, and other diseases are finally formed. Based on the theory of two-phase seepage, the theory of porous media seepage, and the principle of effective stress in porous media, a two-phase fluid-solid coupling mathematical model in saturated zone of subgrade considering the effects of fine particles migration is established. The mathematical model is numerically calculated with the software COMSOL Multiphysics®. The two-phase seepage characteristics and the deformation characteristics of the solid skeleton in saturated zone of the subgrade are studied. The research results show that the volume fraction of fine particles first increases then decreases and finally becomes stable with the increase of time, due to the continuous erosion and migration of fine particles in saturated zone of the subgrade. The volume fraction of fine particles for the upper part of the subgrade is larger than that for the lower part of the subgrade. The porosity, the velocity of fluid, the velocity of fine particles, and the permeability show a trend of increasing first and then stabilizing with time; the pore water pressure has no significant changes with time. The vertical displacement increases first and then decreases slightly with the increase of time, and finally tends to be stable. For the filler with a larger initial volume fraction of fine particles, the maximum value of the volume fraction of fine particles caused by fluid seepage is larger, and the time required to reach the maximum value is shorter. It can be concluded that the volume fraction of fine particles in the subgrade filler should be minimized on the premise that the filler gradation meets the requirements of the specification in actual engineering.

Wavy Motion of Viscous Bubbly Liquid in Tubes of Orthotropic Material

2013 ◽  
pp. 218-227
Author(s):  
Rafael Yusif Amenzadeh ◽  
Akperli Reyhan Sayyad ◽  
Faig Bakhman Ogli Naghiyev
Keyword(s):  
Viscous Fluid ◽  
Numerical Experiment ◽  
Orthotropic Material ◽  
Volume Fraction ◽  
Linear Equations ◽  
Bubbly Liquid ◽  
Flowing Water ◽  
Two Phase ◽  
Infinite Tube ◽  
Limited Process

This article investigates the pulsating flow of a compressible two-phase bubble of viscous fluid contained in an elastic orthotropicle direct axis tube. In this work, one-dimensional linear equations have been used. It is assumed that the tube is rigidly attached to the certain environment. In the case of finite length the pressure is applied at the end of its faces. In the limited process, relations obtained for a very long tube. Such a description, in a sense generalizes and strengthens the work of this type. In the numerical experiment a semi-infinite tube with flowing water containing small amount of air bubbles is considered. The influence of volume fraction of bubbles on wave characteristics is determined.

Sign in / Sign up

Export Citation Format

Share Document