scholarly journals Effect of Virtual Mass Force on the Mixed Transport Process in a Multiphase Rotodynamic Pump

2014 ◽  
Vol 6 ◽  
pp. 958352 ◽  
Author(s):  
Zhiyi Yu ◽  
Baoshan Zhu ◽  
Shuliang Cao ◽  
Ying Liu
Keyword(s):  
Transport Process ◽  
Mass Force ◽  
Virtual Mass

Numerical analysis for interphase forces of gas-liquid flow in a multiphase pump

2018 ◽  
Vol 35 (6) ◽  
pp. 2386-2402 ◽  
Author(s):  
Ming Liu ◽  
Shan Cao ◽  
Shuliang Cao
Keyword(s):  
Drag Force ◽  
Liquid Flow ◽  
Lift Force ◽  
Turbulent Dispersion ◽  
Dispersion Force ◽  
Mass Force ◽  
Virtual Mass ◽  
Content Type ◽  
Multiphase Pump ◽  
Gas Liquid Flow

Purpose The modeling of interphase forces plays a significant role in the numerical simulation of gas–liquid flow in a rotodynamic multiphase pump, which deserves detailed study. Design/methodology/approach Numerical analysis is conducted to estimate the influence of interphase forces, including drag force, lift force, virtual mass force, wall lubrication force and turbulent dispersion force. Findings The results show that the magnitude of the interphase forces can be sorted by: drag force > virtual mass force > lift force > turbulent dispersion force > wall lubrication force. The relations between interphase forces and velocity difference of gas–liquid flow and also the interphase forces and gas volume fraction are revealed. The distribution characteristics of interphase forces in the passages from impeller inlet to diffuser outlet are illustrated and analyzed. According to the results, apart from the drag force, the virtual mass force, lift force and turbulent dispersion force are required, whereas wall lubrication force can be neglected for numerical simulation of gas–liquid flow in a rotodynamic multiphase pump. Compared with the conventional numerical method which considers drag force only, the relative errors of predicted pressure rise and efficiency based on the proposed numerical method in account of four major forces can be reduced by 4.95 per cent and 3.00 per cent, respectively. Originality value The numerical analysis reveals the magnitude and distribution of interphase forces inside multiphase pump, which is meaningful for the simulation and design of multiphase pump.

scholarly journals Calculation Analysis of Pressure Wave Velocity in Gas and Drilling Mud Two-Phase Fluid in Annulus during Drilling Operations

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Yuanhua Lin ◽  
Xiangwei Kong ◽  
Yijie Qiu ◽  
Qiji Yuan
Keyword(s):  
Wave Velocity ◽  
Void Fraction ◽  
Pressure Wave ◽  
Angular Frequency ◽  
Mass Force ◽  
Virtual Mass ◽  
Drilling Mud ◽  
Influx Rate ◽  
Drilling Operations ◽  
Well Depth

Investigation of propagation characteristics of a pressure wave is of great significance to the solution of the transient pressure problem caused by unsteady operations during management pressure drilling operations. With consideration of the important factors such as virtual mass force, drag force, angular frequency, gas influx rate, pressure, temperature, and well depth, a united wave velocity model has been proposed based on pressure gradient equations in drilling operations, gas-liquid two-fluid model, the gas-drilling mud equations of state, and small perturbation theory. Solved by adopting the Runge-Kutta method, calculation results indicate that the wave velocity and void fraction have different values with respect to well depth. In the annulus, the drop of pressure causes an increase in void fraction along the flow direction. The void fraction increases first slightly and then sharply; correspondingly the wave velocity first gradually decreases and then slightly increases. In general, the wave velocity tends to increase with the increase in back pressure and the decrease of gas influx rate and angular frequency, significantly in low range. Taking the virtual mass force into account, the dispersion characteristic of the pressure wave weakens obviously, especially at the position close to the wellhead.

Dense Suspension Flows: a Mathematical Model Consistent with Thermodynamics

2021 ◽  
Author(s):  
Vladimir Shelukhin ◽  
Vladimir Neverov
Keyword(s):  
Mass Concentration ◽  
Mass Force ◽  
Continuum Thermodynamics ◽  
Flux Vector ◽  
Virtual Mass ◽  
Suspension Flows ◽  
Dense Suspension ◽  
Dense Suspensions ◽  
Archimedes Force ◽  
Particle Mass Concentration

Abstract We address the flows of dense suspensions of particles within the framework of two-velocity continuum. Thermodynamics of such a continuum is developed by the method suggested in the papers of L. D. Landau and I. M. Khalatnikov. As an application, we consider the convective settling problem. We capture the Boycott effect and prove that the enhanced sedimentation occurs in a 10 tilted vessel due to vortices. We do not call on additional interphase forces like the Stokes drag, the virtual mass force, the Archimedes force, the Basset-Boussinesq force and etc. Instead, we apply a generalized Fick's law for the particle mass concentration flux vector.

scholarly journals Effect of virtual mass force on prediction of pressure changes in condensing tubes

2012 ◽  
Vol 16 (2) ◽  
pp. 613-622 ◽  
Author(s):  
Hamid Saffari ◽  
Nemat Daur
Keyword(s):  
Experimental Data ◽  
Annular Flow ◽  
Fluid Model ◽  
Mass Force ◽  
Virtual Mass ◽  
Vertical Pipe ◽  
Pressure Drops ◽  
Factors Affecting ◽  
Pressure Changes ◽  
Significant Factors

Three-fluid model is used to calculate the pressure drops in a vertical pipe with the annular flow pattern for condensing steam. The three-fluid models are based on the mass, momentum, and energy balance equations for each of the fluid streams in the annular flow. There are discrepancies between predictions of three-fluid model for pressure drops and the experimental data for pressure drops when using the avail?able correlations for steam-film interfacial friction. The correlation by Stevanovic et at provides good match with experimental data, but it does not take into account some important factors affecting the pressure drops in its three-fluid model. One of these significant factors which is considered in the three fluid model used in the present paper is virtual mass (added mass) force term. Inclusion of the virtual mass force improves the pressure drop predictions such that they agree much better with the experiments.

Analysis of drag and virtual mass forces in bubbly suspensions using an implicit formulation of the lattice Boltzmann method

2002 ◽  
Vol 452 ◽  
pp. 61-96 ◽  
Author(s):  
K. SANKARANARAYANAN ◽  
X. SHAN ◽  
I. G. KEVREKIDIS ◽  
S. SUNDARESAN
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Volume Fraction ◽  
Computational Cost ◽  
Computational Experiments ◽  
Mass Force ◽  
Virtual Mass ◽  
Time Step ◽  
Mass Coefficient ◽  
Boltzmann Method

We present closures for the drag and virtual mass force terms appearing in a two-fluid model for flow of a mixture consisting of uniformly sized gas bubbles dispersed in a liquid. These closures were deduced through computational experiments performed using an implicit formulation of the lattice Boltzmann method with a BGK collision model. Unlike the explicit schemes described in the literature, this implicit implementation requires iterative calculations, which, however, are local in nature. While the computational cost per time step is modestly increased, the implicit scheme dramatically expands the parameter space in multiphase flow calculations which can be simulated economically. The closure relations obtained in our study are limited to a regular array of uniformly sized bubbles and were obtained by simulating the rise behaviour of a single bubble in a periodic box. The effect of volume fraction on the rise characteristics was probed by changing the size of the box relative to that of the bubble. While spherical bubbles exhibited the expected hindered rise behaviour, highly distorted bubbles tended to rise cooperatively. The closure for the drag force, obtained in our study through computational experiments, captured both hindered and cooperative rise. A simple model for the virtual mass coefficient, applicable to both spherical and distorted bubbles, was also obtained by fitting simulation results. The virtual mass coefficient for isolated bubbles could be correlated with the aspect ratio of the bubbles.

scholarly journals Interphase force analysis for air-water bubbly flow in a multiphase rotodynamic pump

2015 ◽  
Vol 32 (7) ◽  
pp. 2166-2180 ◽  
Author(s):  
Zhiyi Yu ◽  
Baoshan Zhu ◽  
Shuliang Cao
Keyword(s):  
Drag Force ◽  
Rotational Speed ◽  
Bubbly Flow ◽  
Turbulent Dispersion ◽  
Sensitivity Analyses ◽  
Dispersion Force ◽  
Mass Force ◽  
Relative Importance ◽  
Virtual Mass ◽  
Content Type

Purpose – Interphase forces between the gas and liquid phases determine many phenomena in bubbly flow. For the interphase forces in a multiphase rotodynamic pump, the magnitude analysis was carried out within the framework of two-fluid model. The purpose of this paper is to clarify the relative importance of various interphase forces on the mixed transport process, and the findings herein will be a base for the future study on the mechanism of the gas blockage phenomenon, which is the most challenging issue for such pumps. Design/methodology/approach – Four types of interphase forces, i.e. drag force, lift force, virtual mass force and turbulent dispersion force (TDF) were taken into account. By comparing with the experiment in the respect of the head performance, the effectiveness of the numerical model was validated. In conditions of different inlet gas void fractions, bubble diameters and rotational speeds, the magnitude analyses were made for the interphase forces. Findings – The results demonstrate that the TDF can be neglected in the running of the multiphase rotodynamic pump; the drag force is dominant in the impeller region and the outlet extended region. The sensitivity analyses of the bubble diameter and the rotational speed were also performed. It is found that larger bubble size is accompanied by smaller predicted drag but larger predicted lift and virtual mass, while the increase of the rotational speed can raise all the interphase forces mentioned above. Originality/value – This paper has revealed the magnitude information and the relative importance of the interphase forces in a multiphase rotodynamic pump.

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