Experimental Validation of Multiphase Flow Models and Testing of Multiphase Flow Meters: A Critical Review of Flow Loops Worldwide

Around the world, research into multiphase flow is performed by scientists with hugely diverse backgrounds: physicists, mathematicians and engineers from mechanical, nuclear, chemical, civil, petroleum, environmental and aerospace disciplines. Multiphase flow models are required to investigate the co-current or counter-current flow of different fluid phases under a wide range of pressure and temperature conditions and in several different configurations. To compliment this theoretical effort, measurements at controlled experimental conditions are required to verify multiphase flow models and assess their range of applicability, which has given rise to a large number of multiphase flow loops around the world. These flow loops are also used intensively to test and validate multiphase flow meters, which are devices for the in-line measurement of multiphase flow streams without separation of the phases. However, there are numerous multiphase flow varieties due to differences in pressure and temperature, fluids, flow regimes, pipe geometry, inclination and diameter, so a flow loop cannot represent all possible situations. Even when experiments in a given flow loop are believed to be sufficiently exhaustive for a specific study area, the real conditions encountered in the field tend to be very different from those recreated in the research facility. This paper presents a critical review of multiphase flow loops around the world, highlighting the pros and cons of each facility with regard to reproducing and monitoring different multiphase flow situations. The authors suggest a way forward for new developments in this area

Multiphase induction motor drives - a technology status review

The area of multiphase variable-speed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Research has been conducted worldwide and numerous interesting developments have been reported in the literature. An attempt is made to provide a detailed overview of the current state-of-the-art in this area. The elaborated aspects include advantages of multiphase induction machines, modelling of multiphase induction machines, basic vector control and direct torque control schemes and PWM control of multiphase voltage source inverters. The authors also provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as an overview of the approaches to the design of fault tolerant strategies for post-fault drive operation, and a discussion of multiphase multi-motor drives with single inverter supply. Experimental results, collected from various multiphase induction motor drive laboratory rigs, are also included to facilitate the understanding of the drive operatio

Experimental validation of multiphase flow models and testing of multiphase flow meters: A critical review of flow loops worldwide

Around the world, research into multiphase flow is performed by scientists with hugely diverse backgrounds: physicists, mathematicians and engineers from mechanical, nuclear, chemical, civil, petroleum, environmental and aerospace disciplines. Multiphase flow models are required to investigate the co-current or counter-current flow of different fluid phases under a wide range of pressure and temperature conditions and in several different configurations. To compliment this theoretical effort, measurements at controlled experimental conditions are required to verify multiphase flow models and assess their range of applicability, which has given rise to a large number of multiphase flow loops around the world. These flow loops are also used intensively to test and validate multiphase flow meters, which are devices for the in-line measurement of multiphase flow streams without separation of the phases. However, there are numerous multiphase flow varieties due to differences in pressure and temperature, fluids, flow regimes, pipe geometry, inclination and diameter, so a flow loop cannot represent all possible situations. Even when experiments in a given flow loop are believed to be sufficiently exhaustive for a specific study area, the real conditions encountered in the field tend to be very different from those recreated in the research facility. This paper presents a critical review of multiphase flow loops around the world, highlighting the pros and cons of each facility with regard to reproducing and monitoring different multiphase flow situations. The authors suggest a way forward for new developments in this area

A High Performance Lattice Boltzmann Solver with Applications to Multiphase Flow in Porous Media

Multiphase flow is significant to many industrial processes such as the geologic storage of CO2 and oil recovery. Microscale simulation of flow in complex geological formations such as saline aquifers or oilfields is a complex and challenging task. The main goal of our study is to overcome high computational demand of multiphase flow simulations by using high performance computing. To model multiphase flow in porous media, we used a multiphase flow lattice Boltzmann (LB) method, which is recognized as an alternative to the classical computational fluid dynamics (CFD) methods. The developed LB model used an extended Color-Gradient approach with improved numerical stability, and it can be used to compute multiphase flow simulations with low capillary number and high viscosity ratios. To optimize computational efficiency, we apply the LB model to a parallel scheme written in C++ using the Message Passing Interface (MPI). Highly parallel runs of these simulations were performed using the HPC system at the Texas Advanced Computing Center at the University of Texas at Austin. We herein introduce the capability of our tool for multiphase flow simulation in porous media and present its application to CO2 sequestration in geological formations. The model has been applied to the simulation of CO2 and brine in sandstone rocks, by employing three-dimensional micro-CT images of rock samples. Injection of supercritical CO2 into the brine-saturated rock samples is simulated and complex displacement patterns under various reservoir conditions are identified.Texas Advanced Computing Center (TACC

A Machine Learning Approach for Virtual Flow Metering and Forecasting

We are concerned with robust and accurate forecasting of multiphase flow rates in wells and pipelines during oil and gas production. In practice, the possibility to physically measure the rates is often limited; besides, it is desirable to estimate future values of multiphase rates based on the previous behavior of the system. In this work, we demonstrate that a Long Short-Term Memory (LSTM) recurrent artificial network is able not only to accurately estimate the multiphase rates at current time (i.e., act as a virtual flow meter), but also to forecast the rates for a sequence of future time instants. For a synthetic severe slugging case, LSTM forecasts compare favorably with the results of hydrodynamical modeling. LSTM results for a realistic noizy dataset of a variable rate well test show that the model can also successfully forecast multiphase rates for a system with changing flow patterns

Droplet collision simulation by multi-speed lattice Boltzmann method

Realization of the Shan-Chen multiphase flow lattice Boltzmann model is considered in the framework of the higher-order Galilean invariant lattices. The present multiphase lattice Boltzmann model is used in two dimensional simulation of droplet collisions at high Weber numbers. Results are found to be in a good agreement with experimental findings

pH-responsive gas–water–solid interface for multiphase catalysis

© 2015 American Chemical Society. Despite their wide utility in laboratory synthesis and industrial fabrication, gas-water-solid multiphase catalysis reactions often suffer from low reaction efficiency because of the low solubility of gases in water. Using a surface-modification protocol, interface-active silica nanoparticles were synthesized. Such nanoparticles can assemble at the gas-water interface, stabilizing micrometer-sized gas bubbles in water, and disassemble by tuning of the aqueous phase pH. The ability to stabilize gas microbubbles can be finely tuned through variation of the surface-modification protocol. As proof of this concept, Pd and Au were deposited on these silica nanoparticles, leading to interface-active catalysts for aqueous hydrogenation and oxidation, respectively. With such catalysts, conventional gas-water-solid multiphase reactions can be transformed to H 2 or O 2 microbubble reaction systems. The resultant microbubble reaction systems exhibit significant catalysis efficiency enhancement effects compared with conventional multiphase reactions. The significant improvement is attributed to the pronounced increase in reaction interface area that allows for the direct contact of gas, water, and solid phases. At the end of reaction, the microbubbles can be removed from the reaction systems through changing the pH, allowing product separation and catalyst recycling. Interestingly, the alcohol oxidation activation energy for the microbubble systems is much lower than that for the conventional multiphase reaction, also indicating that the developed microbubble system may be a valuable platform to design innovative multiphase catalysis reactions