In case of poor-quality oil refining in the oil pipeline, water accumulations are formed, increasing hydraulic losses during transportation and contributing to corrosion processes. Hydrodynamic cleaning, which uses pumped oil flow, has been investigated due to its cost-effectiveness and adaptability for pipelines of varying diameters. This study develops a finite element hydrodynamic model to simulate the removal of water accumulations from inclined pipelines (inclination angle α = 45°). The model reveals a clear relationship between inlet velocity and Multiphase flow patterns, demonstrating transitions from stratified flow (ST) at velocities below 0.1 m/s, to stratified with mixing (ST&MI) at 0.1–0.2 m/s, and finally to a dispersed water-in-oil (DW/O) pattern beyond 0.2 m/s. These velocity transitions are achieved in controlled steps: a steady increase to 0.1 m/s within 20 seconds, followed by acceleration phases reaching 0.25 m/s by 100 seconds. The DW/O regime exhibits the highest cleaning efficiency, reducing water volume from 660 ml to 273.29 ml over 125 seconds—a 58.5% reduction. The analysis further shows an initial rise in pressure gradient within the ST regime, peaking during the first plateau (0.1 m/s) before stabilizing and significantly declining in the DW/O regime at velocities exceeding 0.25 m/s. These findings emphasize the importance of optimizing flow velocity to achieve effective water removal while minimizing hydraulic losses. The study also highlights limitations in existing experimental setups, which predominantly use small diameters (<50 mm), and underscores the need for larger-scale experiments to validate these findings in real-world pipeline operations.

This paper presents soft sensor as a Multiphase flow meter. Nonlinear observer with Ensemble Kalman filter (EnKF) by Navier Stocks equations for inline flow is used to estimate the oil and gas flow. Finite element method and EnKF are used along two scenarios; in addition، in the first scenario، the estimation is done with the refinery output measurement; and in the second scenario، this estimation is done with the production unit output measurement. In this article، we don’ t use primary element for Multiphase flow measurement، instead of that flow will be estimated using some secondary variables (like pressure، temperature، output single phase flow، phase fraction and etc that can be measured directly with high accuracy). Results of comparison between two mentioned scenarios show that also the estimation with output measurement is not accurate، but the accuracy and repeatability of second scenario (estimation with production unit measurement) is in the acceptable standard range. Thus we can conclude that this soft sensor can be used as a backup for primary system and also as a primary system for Multiphase flow measurement.

The Fluid Catalytic Cracking (FCC) is an important process for profitable conversion of heavy hydrocarbons into valuable products. In this study, a CFD simulation of hydrodynamic and heat transfer of FCC gas-liquidsolid riser reactor was carried out by considering the evaporation of liquid droplets. Since there is no symmetry in fluidizing steam, catalyst particles, and atomized liquid droplets, the reactor was modeled as a 3-D system. An Eulerian model was used for both gas and catalyst particles, which is comprised of continuity and momentum, species, heat transfer equations for gas and solid phases, and an equation for solid granular temperature. The hydrodynamic and heat and mass transfer (evaporating liquid droplets) were modeled using Lagrangian approach. The reactor hydrodynamic model predictions were compared with corresponding experimental data reported in the literature to validate the model. The distributions of gas and catalyst velocity are in good agreement with the experimental data. The Multiphase results include flow field, distributions of volume fraction of each phase, temperature profiles of gas and solid phases as well as variation of atomized liquid droplet diameter and temperature. The simulation results indicate that the heating of liquid droplets takes place proportional to their initial size and immediately. Therefore, this step is not the controlling part of FCC riser operation. When the evaporation of the liquid starts, rate of droplet evaporation and reduction in droplet diameter are low. When the droplet temperature reaches the boiling point, the droplet diameter decreases faster and the total mass of liquid droplet evaporates in a fraction of riser reactor. In this research, a correlation for droplet evaporation time was also developed.

The blade inclination angle of soybean milk machine is a key geometric parameter for efficient crushing. For the purpose of obtaining optimal design, the gas-liquid two-phase flow field inside a soybean milk machine is simulated. The gas holdup from simulation is in agreement with the experiment. The simulation result shows that the lower blade A has a great influence on the internal flow field of soybean milk machine, while the upper blade B has a small influence on the flow field. As the angle l αA l increases, the peak value of radial velocity decreases and moves to the interior of the cavity, so does the total pressure. When αA changes from-24° to-26°, the velocity vector at the bottom of the cavity changes from the connected state to the separated state, and the pressure difference between the up and the bottom surface of blade A becomes large. When αA = 24°, the flow field has the strongest turbulent kinetic energy and dissipation. When αB =28°, the pressure difference reaches the maximum. In summary, the best inclination angles are αAopt =-24° ∼-26° and αBopt =28°, respectively.

Multiphase fluid flows occur when two or more fluids that could not be able to mix (such as air and water) find an interface. Multiphase flows can be categorized to single component Multiphase fluids, e. g., water and vapor, and multi-component Multiphase fluids such as oil-water mixture in porous media. These Multiphase flow modeling methods that are divided into microscopic, mesoscopic and macroscopic approaches have been the major focus of this review paper by emphasizing on the methods of population balance model, level set, phase field, lattice boltzmann, size exclusion, front-tracking, and volume of fluid. As result of this study, it could be mentioned that the front-tracking and phase field methods could be accounted as methods with high accuracy and that level set and volume of fluid methods are conceptually simple, while the phase field methods are struggling with complex computational analysis. Achieving to the numerical instability like what happens to the lattice Boltzmann method is more probable than phase field and volume of fluid method. Less time is the main advantage of the lattice Boltzmann method while the population balance method is suffering from long time of analysis. Finally, selection of an appropriate methods most be excuted based on concept of problem, time, cost and accuracy of considering systems.

: Multiphase flows are a major part of many industrial processes, and therefore their monitoring and control is importance. Density is one of the most important characteristics of fluid and its online measurement is essential for the fluid monitoring and control. In this research, an applied current magnetic induction tomography (AC-MIT) system was designed and constructed to measure the density of Multiphase flow in pipeline. The main components of the AC-MIT system include the transmitter and receiver sensors, data acquisition system and problem solving algorithm. In AC-MIT system, innovative transmitter sensors were used, which include two annular electrodes and mounted on the wall of the media. Receiver sensors include a number of coils that are installed around the media. Iterative Gauss-Newton algorithm with Tikhonov regularization method was used to solve the inverse problem. To evaluate performance of the AC-MIT system, Saline water and soil-sand mixture were used as the liquid and solid phase, respectively. The effect of temperature and salinity levels (Five different temperature and salinity levels) was investigated using the response surface method and ANOVA. The results showed that there is a linear relationship between the mass concentrations measured in the two modes (manual measurement and measured by AC-MIT system) with an acceptable coefficient of determination (R2 in the range of 0.98 to 0.99). The results of statistical analysis showed that different levels of temperature and salinity of the carrier phase as well as the interaction of temperature and salinity did not have a significant effect on system performance.

Cavitating flow through the nozzle is numerically simulated by using the Multiphase lattice Boltzmann method. The pseudo-potential Shan-Chen model is used to resolve inter-particle interactions, modeling phase change between the liquid and vapor phases and imposing the surface tension at the interface. The numerical algorithm implemented is simple for programming and efficient for simulation of Multiphase cavitating flows comparing to the traditional Navier-Stokes solvers with complicated cavitation models. Efficiency and accuracy of the Multiphase lattice Boltzmann method with Shan-Chen model for simulation of cavitating flows through the nozzle are examined by computing the cavitation inception, growth and collapse and the results obtained are compared with the existing numerical results in the literature. The study shows that the present computational technique is robust and efficient to predict the cavitation phenomena in the geometries studied.

Non-uniform grids inevitably arise in Multiphase flow simulation scenarios due to the need to resolve near-wall phenomena and/or large L/D ratios associated with the reactor configuration. This in conjunction with large density ratios of the constituent phases can retard the convergence of the pressure-correction equation that results from applying operator-splitting methods to the incompressible Navier-Stokes equations. Various pre-conditioning strategies to this ill-conditioned pressurecorrection matrix are explored in this study for a class of bubbling bed simulations encompassing: different particle densities, bedheights and dimensions (2D/3D). The right-side Block Jacobi preconditioning option resulted in a 20-35% decrease in CPU time that correlated well with a decrease in the number of iterations to reach a specified tolerance.