Wavy Motion of Viscous Bubbly Liquid in Tubes of Orthotropic Material

2012 ◽  
Vol 2 (1) ◽  
pp. 39-47
Author(s):  
Rafael Yusif Amenzadeh ◽  
Akperli Reyhan Sayyad ◽  
Faig Bakhman Ogli Naghiyev
Keyword(s):  
Orthotropic Material ◽  
Volume Fraction ◽  
Linear Equations ◽  
Bubbly Liquid ◽  
Air Bubbles ◽  
Two Phase ◽  
One Dimensional ◽  
Wave Characteristics ◽  
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.

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.

scholarly journals The rheology of three-phase suspensions at low bubble capillary number

2015 ◽  
Vol 471 (2173) ◽  
pp. 20140557 ◽  
Author(s):  
J. M. Truby ◽  
S. P. Mueller ◽  
E. W. Llewellin ◽  
H. M. Mader
Keyword(s):  
Capillary Number ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Spherical Particles ◽  
Bubbly Liquid ◽  
Particle Suspension ◽  
Suspension Rheology ◽  
Particle Volume ◽  
Two Phase ◽  
Three Phase

We develop a model for the rheology of a three-phase suspension of bubbles and particles in a Newtonian liquid undergoing steady flow. We adopt an ‘effective-medium’ approach in which the bubbly liquid is treated as a continuous medium which suspends the particles. The resulting three-phase model combines separate two-phase models for bubble suspension rheology and particle suspension rheology, which are taken from the literature. The model is validated against new experimental data for three-phase suspensions of bubbles and spherical particles, collected in the low bubble capillary number regime. Good agreement is found across the experimental range of particle volume fraction ( 0 ≤ ϕ p ≲ 0.5 ) and bubble volume fraction ( 0 ≤ ϕ b ≲ 0.3 ). Consistent with model predictions, experimental results demonstrate that adding bubbles to a dilute particle suspension at low capillarity increases its viscosity, while adding bubbles to a concentrated particle suspension decreases its viscosity. The model accounts for particle anisometry and is easily extended to account for variable capillarity, but has not been experimentally validated for these cases.

Motion stability of a periodic system of bubbles in a liquid

2001 ◽  
Vol 438 ◽  
pp. 247-275 ◽  
Author(s):  
OLEG V. VOINOV
Keyword(s):  
Periodic Structure ◽  
Potential Flow ◽  
Two Phase Flow ◽  
Dimensional Structure ◽  
Bubbly Liquid ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Stability And Instability ◽  
The One

Wave-like motion in a periodic structure of bubbles that steadily moves through ideal incompressible liquid is considered. The wavelength is microscopically short. Some general local properties containing general information about two-phase flow are found. The dynamics of small-amplitude disturbances is studied in linear systems (called trains) and in spatial structures (such as a cubic lattice). The behaviour of one-dimensional waves in various structures is shown to differ widely: one-dimensional waves in the train do not magnify, whereas in the three-dimensional structure there may be stability and instability of one-dimensional waves. In the continuum limit the one-dimensional instability is demonstrated not to be related to the mean parameters of two-phase flow. The long-wave dynamics is shown to depend significantly on the relative velocity vector orientation in the lattice, but orientation is not included in the usual equations for the two-phase continuum. One result of this study is the relation between the short-wave-type instability of the periodic structure, on the one hand, and the instability of one-dimensional flow of inviscid bubbly liquid discovered by van Wijngaarden on the other. Long microscopic waves are analysed to determine the coefficients of one-dimensional equations for a two-phase continuum model. The velocity orientation at which the coefficients of the traditional one-dimensional model are obtained is found. Short waves in a stationary structure are studied by using the system of equations based on the equation of motion of a small sphere in a general potential flow. A refined equation for the force applied on a sphere in a non-uniform potential flow is derived.

scholarly journals A two-phase model for numerical simulation of debris flows

2014 ◽  
Vol 2 (3) ◽  
pp. 2151-2183 ◽  
Author(s):  
S. He ◽  
W. Liu ◽  
C. Ouyang ◽  
X. Li
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Volume Fraction ◽  
Solid Phase ◽  
Fluid Phase ◽  
Viscous Drag ◽  
Finite Volume Scheme ◽  
Viscous Stress ◽  
Two Phase ◽  
One Dimensional

Abstract. Debris flows are multiphase, gravity-driven flows consisting of randomly dispersed interacting phases. The interaction between the solid phase and liquid phase plays a significant role on debris flow motion. This paper presents a new two-phase debris flow model based on the shallow water assumption and depth-average integration. The model employs the Mohr–Coulomb plasticity for the solid stress, and the fluid stress is modeled as a Newtonian viscous stress. The interfacial momentum transfer includes viscous drag, buoyancy and interaction force between solid phase and fluid phase. We solve numerically the one-dimensional model equations by a high-resolution finite volume scheme based on a Roe-type Riemann solver. The model and the numerical method are validated by using one-dimensional dam-break problem. The influences of volume fraction on the motion of debris flow are discussed and comparison between the present model and Pitman's model is presented. Results of numerical experiments demonstrate that viscous stress of fluid phase has significant effect in the process of movement of debris flow and volume fraction of solid phase significantly affects the debris flow dynamics.

Hyperbolicity Analysis of a One-Dimensional Two-Fluid Two-Phase Flow Model for Stratified-Flow Pattern

2015 ◽  
Author(s):  
Carina N. Sondermann ◽  
Rodrigo A. C. Patrício ◽  
Aline B. Figueiredo ◽  
Renan M. Baptista ◽  
Felipe B. F. Rachid ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Numerical Study ◽  
Fluid Model ◽  
Practical Importance ◽  
Stratified Flow ◽  
Hyperbolic Partial Differential Equations ◽  
Two Phase ◽  
One Dimensional ◽  
Flow Models ◽  
Two Fluid

Two-phase flows in pipelines occur in a variety of processes in the nuclear, petroleum and gas industries. Because of the practical importance of accurately predicting steady and unsteady flows along the line, one-dimensional two-fluid flow models have been extensively employed in numerical simulations. These models are usually written as a system of non-linear hyperbolic partial-differential equations, but some of the available formulations are physically inconsistent due to a loss of the hyperbolicity property. In these cases, the associated eigenvalues become complex numbers and the model loses physical meaning locally. This paper presents a numerical study of a one-dimensional single-pressure four-equation two-fluid model for an isothermal stratified flow that occurs in a horizontal pipeline. The diameter, pressure and volume fraction are kept constant, whereas the liquid and gas velocities are varied to cover the entire range of superficial velocities in the stratified region. For each point, the eigenvalues are numerically computed to verify whether they are real numbers and to assess their signs. The results show that hyperbolicity is lost near the boundaries of the stratified pattern and in a vast area of the region itself. Moreover, the eigenvalue signs alternate, which has implications on the prescription of numerical boundary conditions.

On the Numerical Computation for a One-Dimensional Two-Phase Flow Equations

2007 ◽  
Author(s):  
D. Zeidan
Keyword(s):  
Numerical Computation ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Homogeneous Problem ◽  
Phase Flow ◽  
Source Terms ◽  
Two Phase ◽  
Interphase Interaction ◽  
One Dimensional ◽  
Flow Equations

This paper describes the development of an approximate solution for the numerical computation for a one-dimensional two-phase flow equations. The equations include source terms which account for the relaxation of volume fraction and the interfacial fraction. A simple splitting numerical method, which handles separately the homogeneous and source terms problems, is used to compute approximations of the solutions. The homogeneous problem is solved numerically using Godunov methods of centred-type. This solution is then employed in the source terms problem to solve the general initial-value problem for the two-phase flow equations. Numerical results are presented demonstrating the complete approach. The results show that the interphase interaction through the source terms appearing in the equations.

Numerical investigation of cavitation effect on two-phase oil film flow between a friction pair in hydro-viscous drive

2018 ◽  
Vol 232 (24) ◽  
pp. 4626-4636 ◽  
Author(s):  
Fangwei Xie ◽  
Xudong Zheng ◽  
Gang Sheng ◽  
Qi Sun ◽  
Ramesh K Agarwal
Keyword(s):  
Single Phase ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Rotation Speed ◽  
Friction Pair ◽  
Phase Flow ◽  
Air Bubbles ◽  
Two Phase ◽  
Oil Film ◽  
Cavitation Effect

This paper describes a three-dimensional computational model of oil film between a friction pair to investigate the characteristics of both single-phase and two-phase flow of the oil film in hydro-viscous drive. For the single-phase oil film, the distribution of pressure is very regular from inlet to outlet of the friction pair; its value decreases gradually. On the other hand, the temperature in the middle part of the oil film is considerably lower and the velocity increases at a faster rate near the outlet and has a parabolic profile, which is mainly caused by both the shear stress and extrusion force. By comparison, the physical phenomena at the outlet of the oil film are entirely different for two-phase flow with cavitation. For two-phase simulation of flow with cavitation, we first obtain the volume fraction of air bubbles at rotation speeds of 500, 1000, 2000, 3000, and 4000 revolutions/min. With increase in the rotation speed, the volume fraction of air bubbles increases, and their maximum value becomes even greater than 10%. Furthermore, due to cavitation, the torque transferred by the oil film is no longer linear with the rotation speed; its value decreases gradually. These results are important in the study of hydro-viscous drive and its applications; they shed a new light on the mechanism of power transmission through oil film in the presence of cavitation.

A ONE-DIMENSIONAL TWO-PHASE FLOW MODEL AND EXPERIMENTAL VALIDATION FOR A FLASHING VISCOUS LIQUID IN A SPLASH PLATE NOZZLE

2015 ◽  
Vol 25 (9) ◽  
pp. 795-817 ◽  
Author(s):  
Mika P. Jarvinen ◽  
A. E. P. Kankkunen ◽  
R. Virtanen ◽  
P. H. Miikkulainen ◽  
V. P. Heikkila
Keyword(s):  
Viscous Liquid ◽  
Experimental Validation ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional
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