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Unsteady Fluidynamic Behavior of Gas Bubbles Flowing in Curved Pipes: A Numerical Study

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Advances in Chemical Engineering and Science 2012年第2期2卷 283-291页

作者： Jose Luis Gomes Marinho Ramdayal Swarnakar severino rodrigues de farias neto Antonio Gilson Barbosa de Lima department of Chemical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil department of Mechanical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil

Petroleum is considered as one of the factors for the development of a nation as well as a cause of economic and political conflicts around the world because of the diversity of products obtained with their derivatives such as fuel for automotives and aviation, and manufacturing plastic parts, among others. The crude petroleum (usually oil, water and gas) found in an underground reservoir is transported to the surface by pipes, and has drawn the attention of researchers because of the problems generated in the pipeline with particular attention to the loss of pressure, friction and bubbles. For a fluid flow in plug regime, where many of the bubbles formed coalesce and produce bigger ones of sizes almost equal to the pipe diameter (Taylor bubble), severe instability in the flow is caused. In this context, the objective of this research has been to study the Taylor bubble flow in curved ducts using the software CFX. Results of the transient effects of the air concentration on the bubble air volumetric fraction, of the viscosity on bubble format, and pipe angle of 90? on bubble symmetry are presented and interpreted.

关键词： Slug Flow Taylor Bubbles Curved Pipe CFD Oil Simulation

Thermo-Hydrodynamics of Core-Annular Flow of Water, Heavy Oil and Air Using CFX

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Advances in Chemical Engineering and Science 2013年第4期3卷 37-45页

作者： Antonio José Ferreira Gadelha severino rodrigues de farias neto Ramdayal Swarnakar Antonio Gilson Barbosa de Lima department of Chemical Engineering Center of Science and Technology Federal University of Campina Grande

The transport of heavy and ultra-viscous oil employing the core-flow technique has been increasing recently, because it provides a greater reduction of the pressure drop during the flow. In this context, the effect of temperature and the presence of gas on the thermo-hydrodynamics of a three-phase water-heavy oil-air flow in a horizontal pipe under the influence of gravity and drag forces, using the commercial software ANSYS CFX?, have been evaluated. The standard κ ? ε turbulence model, the mixture model for heavy oil-water system and the particle model for heavy oil-gas and water-gas systems, were adopted. Results of velocity, volume fraction, pressure and temperature fields of the phases present along the pipe are presented and discussed. It has been found that the presence of the air phase and the variation in the temperature affect the behavior of annular flow and pressure drop.

关键词： Heavy Oil Three-Phase Flow Heat Numerical Simulation CFX

Non-Isothermal Separation Process of Two-Phase Mixture Water/Ultra-Viscous Heavy Oil by Hydrocyclone

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Advances in Chemical Engineering and Science 2011年第4期1卷 271-279页

作者： Josedite Saraiva de Souza Fabiana Pimentel Macêdo farias Ramdayal Swarnakar severino rodrigues de farias neto Antonio Gilson Barbos de Lima 不详

Environmental agencies do not allow effluents, from the petroleum productions, which contain oil concentrations that exceed the amounts permitted by the regulations. In recent time heavy oil operating petroleum industries are generating oil/water mixture by products, which are difficult to separate. Industrially, hydrocyclone is generally used to separate oil from an oil/water mixture. This is due to its high performance of separation, low cost of installation and maintenance. In the present work, therefore, the thermal fluid dynamics of water/ultra-viscous heavy oil separation process in a hydrocyclone has been studied. A steady state mathematical model which simulates the performance of a non-isothermal separation process is presented. The Eulerian-Eulerian approach for the interface of the phases involved (water/ultra-viscous heavy-oil) is used and the two-phase flow is considered as incompressible, viscous and turbulent. For carrying out numerical solutions of the governing equations the CFX11? commercial code was used. Results of the behavior of the two-fluid flow inside the hydrocyclone and separation efficiency are presented and analyzed. The role of the average temperature of the fluid, oil droplet diameter and the fluid mixture inlet velocity on the separation efficiency of the hydrocyclone are verified.

关键词： Thermal Fluid Dynamics Hydrocyclone Two-Phase Flow Simulation Separation Efficiency

Numerical Analysis of Heavy Oil-Water Flow and Leak detection in Vertical Pipeline

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Advances in Chemical Engineering and Science 2013年第1期3卷 9-15页

作者： Joao Victor Nunes de Sousa Cristiane Holanda Sodré Antonio Gilson Barbosa de Lima severino rodrigues de farias neto department of Mechanical Engineering Center of Sciences and TechnologyFederal University of Campina GrandeCampina GrandeBrazil department of Chemical Engineering Technology CenterFederal University of AlagoasMaceióBrazil department of Chemical Engineering Center of Sciences and TechnologyFederal University of Campina GrandeCampina GrandeBrazil

Pipeline is a conventional, efficient and economic way for oil transportations. The use of a good system for detecting and locating leaks in pipeline contribute significantly to operational safety and cost saving in petroleum industry. This paper aims to study the heavy oil-water flow in vertical ducts including leakage. A transient numerical analysis, using the ANSYS-CFX? 11.0 commercial software is performed. The mathematical modeling considers the effect of drag and gravitational forces between the phases and turbulent flow. Mass flow rate of the phases in the leaking orifice, the pressure drop as a function of the time and the velocity distributions are presented and discussed. We can conclude that volumetric fraction of phases and fluid mixture velocity affect pressure drop and mass flow rate at the leak hole.

关键词： Heavy Oil Multiphase Flow Leakage Numerical Simulation

Numerical Study of Oil/Water Separation by Ceramic Membranes in the Presence of Turbulent Flow

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Advances in Chemical Engineering and Science 2012年第2期2卷 257-265页

作者： Josedite Saraiva de Souza Tássia Mota Vieira Enivaldo Santos Barbosa Acto de Lima Cunha severino rodrigues de farias neto Antonio Gilson Barbosa de Lima department of Chemical Engineering Center of Sciences and Technology Federal University of Campina Grande (UFCG) Campina Grande Brazil department of Mechanical Engineering Center of Sciences and Technology Federal University of Campina Grande (UFCG) Campina Grande Brazil

Disposal of produced water during petroleum extraction causes serious environmental damage, hence the need to complete the water treatment before being disposed to environment within the criteria set established by environmental agencies in the countries. Ceramics membranes have been highlighted as a good device for separating oil/water. These act as a barrier to oil in the aqueous stream, because their essential properties for filtration, such as chemical inertness, biological stability and resistance to high temperatures. The limitation of the separation process is the decay of permeate flux during operation, due to concentration polarization and fouling. In this sense, this paper aims to evaluate numerically the feasibility of the process of separating oil/water by means of ceramic membranes in the presence of a turbulent flow induced by a tangential inlet. The results of the velocity, pressure and volumetric fraction distributions for the simulations different by varying the mass flow rate inlet and different geometric characteristics of the membrane are presented and analyzed.

关键词： Ceramic Membranes Separation Two-Phase Flow Numerical Simulation

Oily Water Treatment by Ceramic Membrane: Modeling and Simulation

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Open Journal of Fluid Dynamics 2021年第1期11卷 1-19页

作者： Adriana Barbosa da Costa Pereira Hortência Luma Fernandes Magalhães Leonardo Pereira de Lucena Silva Cristiane Arcoverde Passos Ricardo Soares Gomez Balbina Raquel de Brito Correia severino rodrigues de farias neto Antonio Gilson Barbosa de Lima department of Chemical Engineering Federal University of Campina Grande Campina Grande Brazil department of Industry Federal Institute of Paraiba Cajazeiras Brazil department of Chemical Engineering Federal University of Paraná Curitiba Brazil department of Mechanical Engineering Federal University of Campina Grande Campina Grande Brazil

The separation process of oily water using membranes has attracted the attention of researchers and engineers. The greater problem in the use of membrane separation process is the reduction in permeate flux due to clogged pores by oil deposition inside the membrane or by the effect of the concentration polarization. For this purpose, a theoretical study of a water/oil separation module was performed. This device consists of a tubular ceramic membrane provided with a rectangular inlet section. Numerical simulations were performed using Ansys CFX software to solve the mass and momentum conservation equations in the fluid and porous domains. Here was adopted the RNG k-ε turbulence model. The effect of the membrane porosity and the inlet velocity of the fluid mixture on the two-phase flow behavior inside the separation module were evaluated. Results of the volumetric fraction, velocity and pressure fields of the oil and water phases are presented and analyzed. The results indicate a higher oil concentration within the membrane for the cases of higher porosity, and that the inlet fluid mixture velocity does not substantially affect the velocity profile within the separation module. It is found that the maximum separation efficiency of the module was obtained with feed velocity of 40 m/s and membrane porosity of 0.44.

关键词： Ceramic Membranes Separation Process Computational Fluid Dynamics CFX

Using hot-vapor bypass for pressure control in distillation columns

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Chinese Journal of Chemical Engineering 2018年第1期26卷 144-151页

作者： Stefano Ciannella Arthur Siqueira Damasceno Icaro Caze Nunes Gilvan Wanderley de farias neto Wagner Brandao Ramos Romildo Pereira Brito department of Chemical Engineering Federal University of Campina GrandeCarnpina Grande 58109-970ParafbaBrazil

Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to be controlled. However, there are few studies about how pressure affects the dynamic behavior of distillation columns and most research on distillation column control involve direct manipulation of cooling fluid through the condenser. Nevertheless, such an approach demands constant changes in cooling fluid flowrates that are commonly by the order of tons per hour, which can be difficult to work or even unfeasible in a real plant. Furthermore, this strategy is usually avoided, as it can cause fouling and corrosion acceleration. The hot-vapor bypass strategy fits well as a solution for these issues, eliminating the need to dynamically manipulate cooling fluid flowrates in the condensation unit. This work presents the modeling and simulation of a conventional distillation column for the separation of water and ethanol, in which a comparative study between a conventional pressure control and a control using hot-vapor bypass was performed. The main results were obtained through dynamic simulations which considered various disturbances in the feed stream, and demonstrated superior performance by the hot-vapor bypass system over the usual scheme proposed in literature, while evaluating the lntegral Absolute Error （IAE） norm as the control performance index.

关键词： Distillation Pressure control Hot-vapor bypass

Parsonage-Turner syndrome following chikungunya virus infection:A case report

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Asian Pacific Journal of Tropical Medicine 2019年第5期12卷 239-242页

作者： Luis Arthur Brasil Gadelha farias Marina Vasconcelos Sampaio Ant?nio Carlos delgado Sampaio Roberto da Justa Pires neto Jorge Luiz Nobre rodrigues School of Medicine,Federal University of Ceará School of Medicine,Universitary Center Christus(Unichristus) Orthopedic department,S?o Carlos Hospital Hospital S?o Joséde Doen?as Infecciosas Infectology Service,Walter Cantídeo University Hospital School of Medicine Federal University of Ceará School of Medicine Universitary Center Christus(Unichristus) Orthopedic department Sao Carlos Hospital Hospital Sao José de Doencas Infecciosas Infectology Service Walter Cantídeo University Hospital

Rationale: Parsonage-Turner syndrome is a rare syndrome of unknown etiology, affecting mainly the lower motor neurons of the brachial *** fever is a mosquito-borne viral disease characterized by acute fever and polyarthritis/*** concerns: A 54-year-old Brazilian male patient who presented with a 2-day history of fever(temperature 38.8 ℃), arthralgia, erythematous rash, diffuse osteomuscular pain and headache, which evolved into left shoulder pain associated with morning ***: Parsonage-Turner syndrome and chikungunya ***: Symptomatic treatment(a combination of short-acting dypirone(500 mg every 6 h) and slow-release opioids(tramadol 100 mg every 4 h) and physiotherapy/rehabilitation with ***: The patient was improved and discharged, remaining with symptomatic treatment and physiotherapy/***: To the best of our knowledge, there were no reports of Parsonage-Turner syndrome following chikungunya virus *** of the possibility of this rare association is *** present case report highlights the importance of awareness of this association as a new cause of morbidity in patients with chikungunya virus infection.

关键词： Parsonage-Turner syndrome Chikungunya virus Chikungunya fever Brachial amyotrophy Case report

Acute kidney injury in leptospirosis:Overview and perspectives

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Asian Pacific Journal of Tropical Medicine 2018年第10期11卷 549-554页

作者： Geraldo Bezerra da Silva Junior Nattachai Srisawat Gabriela Studart Galdino ênio Sima Macedo JoséReginaldo Pinto Geysa Maria Nogueira farias Renan Lima Alencar Roberto da Justa Pires neto Elvino JoséGuardao Barros Elizabeth de Francesco Daher Medical Sciences and Public Health and Graduate Programs School of Medicine Health Sciences Center University of Fortaleza Excellence Center for Critical Care Nephrology Division of Nephrology Department of Medicine Chulalongkorn University Collaborating CRISMA faculty member Department of Critical Care Medicine Univeristy of Pittsburgh School of Medicine Medical Sciences and Public Health Graduate Programs Department of Internal Medicine School of Medicine Federal University of Ceara department of Internal Medicine School of Medicine Federal University of Rio Grande do Sul

Leptospirosis is a bacterial disease disseminated through the centuries in the whole world which causes symptoms that go from self-limited diseases to hemorrhagic manifestations and organ failure, including acute kidney injury(AKI), composing the severe disease known as the Weil's syndrome. Mortality rates varies according to the clinical presentation and usually increases when kidney injury is present, and is even higher in the setting of pulmonary hemorrhage. There are recent advances in the search for novel biomarkers of renal involvement and early detection of AKI in leptospirosis, as well as in its pathophysiology. We review in this article the clinical aspects of leptospirosis-associated AKI and the perspectives for future research.

关键词： Leptospirosis Acute kidney injury Perspectives Bacterial infections