The Study of Electrode Size on Sensitive Field Effect of Electromagnetic Flow Meter in the Measuring Fluids Containing Non-Conductive Body

2013 ◽  
Vol 756-759 ◽  
pp. 551-555
Author(s):  
Yue Ming Wang ◽  
Ling Fu Kong ◽  
Ying Wei Li
Keyword(s):  
Phase Flow ◽  
Flow Meter ◽  
Two Phase ◽  
Electrode Size ◽  
Electromagnetic Flow ◽  
Response Characteristics ◽  
Conductive Body ◽  
Multi Phase Flow ◽  
Electromagnetic Flow Meter ◽  
Multi Phase

Electromagnetic flow meters are widely used in two-phase or multi-phase flow measurements in recent years. In this paper, simulation model is established to study the flow meter response characteristics which exist a non-conductive body (oil bubble) in the fluid by use finite element software ANSYS. We analyze different electrode size impact on the response characteristics of electromagnetic flow meter in the measurement of two-phase or multi-phase flow which includes non-conductive material in the fluid, which provides reference for design of the sensor electrode sizes, and provides a theoretical basis for error analysis measuring two-phase or multi-phase flow under different electrode sizes of electromagnetic flowmeter.

Computational Fluid Dynamics for the Simulation of Oil Recovery Systems at High Seas

2006 ◽  
Author(s):  
Gu¨nther F. Clauss ◽  
Sascha Kosleck ◽  
Mazen Abu-Amro
Keyword(s):  
Oil Recovery ◽  
Stokes Equations ◽  
Model Tests ◽  
Body Motion ◽  
Phase Flow ◽  
Two Phase ◽  
Local Flow ◽  
Element Discretization ◽  
Multi Phase Flow ◽  
Multi Phase

The paper presents multi-phase CFD-Calculations for simulating oil skimming processes in heavy seas. During the last years tanker catastrophes showed the shortcomings of existing oil recovery systems, especially while operating in heavy seas. For developing new and more efficient devices complex and expensive model tests must be conducted under special conditions to prevent environmental pollution. To minimize these costs CFD-tools for multi-phase flow simulations have been developed, and are applied to analyse and optimize oil recovery devices. The analysis of local flow phenomena dependent on the motion of an oil recovery system in a given sea state are the basis for the development of an optimized oil recovery device. For this purpose, existing nonlinear numerical methods used for stationary and unsteady viscous computation (based on Volume of Fluid (VOF) methods and Reynolds Averaged Navier Stokes Equations (RANSE)) are enhanced and combined to simulate two-phase (air, water) and three-phase-flow (air, water, oil). New methods for simulating motions in three (2D) and six degrees (3D) of freedom as well as for the generation of waves — regular and irregular sea states — are developed. To increase the speed of calculation the RANSE/VOF-method is coupled with a Potential theory method using Finite Element discretization (Pot/FE). Combining the advantage of the Pot/FE-solver, i.e. calculation speed, with the possibilities of the RANSE/VOF-solver to simulate multi-phase flow and free body motion offers the opportunity to simulate a complete test in reasonable time. To validate the procedure, the numerical simulations are compared to WAMIT-calculations and model tests carried out in a physical wave tank.

Development of a Simplified Methodology for Evaluation of Piping Vibration due to Multi-Phase Flow

2015 ◽  
Author(s):  
Humberto R. Santos ◽  
Michèle S. Pfeil ◽  
Ediberto B. Tinoco ◽  
Ronaldo C. Battista
Keyword(s):  
Boundary Conditions ◽  
Multiphase Flow ◽  
Feasible Solution ◽  
Piping System ◽  
Phase Flow ◽  
Two Phase ◽  
Multi Phase Flow ◽  
The One ◽  
Multi Phase ◽  
Acceleration Signals

Excessive piping vibration is a major cause of idleness, leaks, failures, fires and explosions in the petrochemical industry. One of the causes of vibration in piping is the occurrence of multiphase flow regimes, specially the one called slug flow. The main purpose of this work is the verification and improvement of a methodology for evaluation of excessive piping vibration caused by multiphase flow. This methodology is capable of generating, from the measured acceleration signals, forces equivalent to those induced by the two-phase flow. In other words, this methodology enables simplified models to represent adequately the dynamic structural behavior of the piping system when new boundary conditions are imposed, allowing to estimate the risk of failure in operation of piping system or to propose technically feasible solution to mitigate the vibration problem. A physical model made of acrylic pipes and PVC bends was assembled and used to measure, simultaneously, the accelerations at four points of this loop when subjected to multiphase flow and with two different boundary conditions. The methodology could therefore be applied, refined, and validated with the data obtained from the experiment and with the aid of numerical simulation.

A Two-Phase Flow Solver for Incompressible Viscous Fluids, Using a Pure Streamfunction Formulation and the Volume of Fluid Technique

2014 ◽  
Vol 348 ◽  
pp. 9-19 ◽  
Author(s):  
Raphaël Comminal ◽  
Jon Spangenberg ◽  
Jesper Henri Hattel
Keyword(s):  
Two Phase Flow ◽  
Volume Of Fluid ◽  
Viscous Fluids ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver ◽  
Incompressible Viscous Fluids ◽  
Multi Phase Flow ◽  
Low Reynolds ◽  
Multi Phase

Accurate multi-phase flow solvers at low Reynolds number are of particular interest for the simulation of interface instabilities in the co-processing of multilayered material. We present a two-phase flow solver for incompressible viscous fluids which uses the streamfunction as the primary variable of the flow. Contrary to fractional step methods, the streamfunction formulation eliminates the pressure unknowns, and automatically fulfills the incompressibility constraint by construction. As a result, the method circumvents the loss of temporal accuracy at low Reynolds numbers. The interface is tracked by the Volume-of-Fluid technique and the interaction with the streamfunction formulation is investigated by examining the Rayleigh-Taylor instability and broken dam problem. The results of the solver are in good agreement with previously published theoretical and experimental results of the first and latter mentioned problem, respectively.

Numerical Simulation and Experimental Validation of Three-Dimensional Unsteady Multi-Phase Flow in Flushing Process of Toilets

2013 ◽  
Vol 444-445 ◽  
pp. 304-311 ◽  
Author(s):  
Jian Guo Hu ◽  
You Song Sun ◽  
Zheng Rong Zhang
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
High Viscosity ◽  
Coupling Scheme ◽  
Phase Flow ◽  
Two Phase ◽  
Discrete Equations ◽  
Vof Model ◽  
Multi Phase Flow ◽  
Multi Phase

In order to predict the flush performances of digital toilet products before mass production, a numerical simulation for a three-dimensional unsteady multi-phase flow in the flushing process of a wash-down toilet is carried out by using FLUENT software. The finite volume method (FVM) is used to discrete the three governing equations in space and time. The discrete equations are solved by using the first-order upwind discretization scheme and the PISO pressure-velocity coupling scheme. The realizable turbulence model is chosen as the viscous model to treat the fluid flow with large bending curvature wall. The volume of fluid (VOF) model is applied to solve the transient free-surface problem. First, a two-phase flow was simulated on the assumption that there is not sewage but water in the trap seal. Then, by simplifying the mixture of sewage and water in the trap seal as the third phase with high viscosity, a three-phase flow was simulated. Moreover, in order to validate the simulated results, a flushing testing was conducted to test the flush range, and a target type flow meter was designed, calibrated and applied to test the flush velocity. The comparisons show a good agreement between the numerical and experimental results. Based on the verified simulation results, the flush performances of the digital wash-down toilet, such as flush range, flush velocity and sewage replacement ability, can be predicted and evaluated.

Study of Sensor of Electrical Capacitance Tomography (ECT) System Based on COMSOL

2013 ◽  
Vol 734-737 ◽  
pp. 3016-3021 ◽  
Author(s):  
Hai Yan Cao ◽  
Xue Mei Duan ◽  
Hua Xiang Wang
Keyword(s):  
Electrical Capacitance Tomography ◽  
Phase Flow ◽  
Electrical Capacitance ◽  
Two Phase ◽  
Simulation Research ◽  
Three Phase Flow ◽  
Multi Phase Flow ◽  
A New Technique ◽  
Multi Phase ◽  
Capacitance Tomography

Electrical Capacitance Tomography technique is a new technique for multi-phase flow measurement. With broad application prospects, the purpose of this technique is to identify each phases composition of two-phase/multi-phase flow system in a closed pipe. A new method COMSOL was used to analysis the electrical capacitance tomography of reconstruction image and simulation research. First of all, different electrical models were established, and the reconstruction images of four kinds of representative flow were achieved; In addition, through simulation study of the field with disperse phase, the influence of the electrode number, shielding case and radial electrode to the imaging quality were analyzed; Finally, the reconstruction images of three-phase flow were achieved to obtain the satisfactory result.

scholarly journals A maximum principle for multiphase flow models

2017 ◽  
pp. 138-145
Author(s):  
К.А. Новиков
Keyword(s):  
Maximum Principle ◽  
Flow Model ◽  
Maximum Principles ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Models ◽  
Three Phase ◽  
Three Phase Flow ◽  
Multi Phase Flow ◽  
Multi Phase

Сформулированы и доказаны принципы максимума для нескольких моделей многофазной фильтрации. Первый принцип справедлив для фазовых насыщенностей в несжимаемом случае модели двухфазной фильтрации с постоянными вязкостями, а второй - для глобального давления в моделях двух- и трехфазной фильтрации Two maximum principles for several multi-phase flow models are formulated and proved. The first one is valid for phase saturations in an incompressible two-phase flow model with constant viscosities. The second one is valid for the global pressure in two- and three-phase flow models with constant viscosities and is also valid for phase pressures in the case of zero capillary pressure.

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