S. R. Farias Neto

Bio: S. R. Farias Neto is an academic researcher from Federal University of Campina Grande. The author has contributed to research in topics: Pressure drop & Multiphase flow. The author has an hindex of 5, co-authored 11 publications receiving 74 citations.

Heat and Mass Transfer in Porous Materials with Complex Geometry: Fundamentals and Applications

Abstract: This chapter provides information related to simultaneous heat and mass transfer and dimension variations in unsaturated porous bodies of arbitrary shape during transient problems. Two mathematical approaches are presented and discussed: lumped and distributed-parameters models. Here, applications have been given to some engineering processes (cooling, heating and drying). A two-dimensional distributed model written in a orthogonal curvilinear coordinate system and which assumes the pure diffusion as the sole mechanism of heat and moisture transport within the solid is applied to ellipsoidal porous bodies (prolate spheroid). A lumped-parameter model written in any coordinate system which includes effects such as shape of the body, heat and mass generation, evaporation and convection is presented, and analytical solution of the governing equations, limitations of the modeling and general theoretical results are discussed.

Moisture Transport Process in Vegetable Fiber Composites: Theory and Analysis for Technological Applications

Abstract: This chapter provides theoretical and experimental information about water absorption in unsaturated polyester polymer composites reinforced with vegetable fibers. The use of raw materials from renewable sources, such as natural fibers, has shown great promise in a variety of engineering applications. Composites reinforced with natural fibers are sensitive to influences from environmental agents such as water and temperature. The organic nature of vegetable fibers is responsible for the higher moisture sensitivity of the mechanical properties of natural fiber reinforced composites when compared to synthetic fiber reinforced composites. Here, topics related to theory, experiments, mathematical modeling and numerical procedures, and technological applications for different natural fibers are presented and discussed in detail. Results of microscopy, water absorption kinetics, moisture content distribution, and area/volume relationships for unsaturated polyester composites reinforced with caroa and macambira vegetable fibers are shown and analyzed. The knowledge of moisture distribution allows the determination of areas that may show delamination problems (moisture induced degradation) due to the weakness of the fiber-matrix interface and consequently reduction in the composites mechanical properties.

Numerical simulation of heavy oil flows in pipes using the core-annular flow technique

Abstract: The importance of heavy oils in the world market for petroleum has increased very quickly in the last years. The reserves of heavy oils in the world are estimated at 3 trillion barrels, while reserves of light oils have reduced progressively in the last decade. The high oil viscosity creates major problems in the production and transportation of the oil. This situation leads to the high pressure and power required for its flow, overloading and damaging the equipment, increasing the cost of production. Due to the need to develop new alternatives that will make the production and transport of heavy oil economically viable, this work has the objective to study, numerically, the behavior of isothermal multiphase flow (heavy oil and water), type “core flow”, in pipelines, using the software CFX 3D. The pressure drop was determinated to a core-flow in a pipe with 7 in. diameter, 2.7 Pa.s oil viscosity and water at environment temperature. Results of the pressure, velocity and volume fraction distributions of the phases are presented and analyzed. It was verified that the pressure drop was reduced 58 times when compared to that obtained with oil flow alone in the pipe.

Hydrocyclone applications in produced water: a steady-state numerical analysis

Abstract: Hydrocyclones are devices used to treat produced water in the petroleum industry. These gadgets are employed especially at offshore fields, due to restrictions of charge and space. Several factors may affect the performance of the oil/water separation by hydrocyclones. Among these factors are the geometry and processing capacity of the hydrocyclones, oil droplet size, density difference between the phases, pressure drops, and temperature fluctuation. This paper aims to analyze the effects of inlet fluid mixture temperature and oil droplet size on hydrocyclone performance in separating dispersed heavy oil from continuous streams of water. The experiment used a commercial package, ANSYS CFX 11. Numerical results clearly indicate that superficial velocity and oil mass flow rate in the overflow have a positive relationship with oil droplet size and temperature. The pressure drop decreased from 155.857 to 141.966kPa and the separation efficiency changed from 58.97 to 60.11% when the inlet temperature increased from 20 to 100°C using a 40μm oil droplet diameter.

Natural gas laminar flow in elliptic cylindrical pipes: a numerical study

Abstract: Natural gas consists of a mixture of inorganic gases and saturated hydrocarbons containing mainly methane. Once extracted from the underground, the natural gas, either in the gaseous phase or liquefied, should be transported until the consumption zones in circular pipes, or pipelines. Many theoretical studies have been reported focusing on the fluid flow in such pipes, but little attention has been given to elliptic cylindrical pipes, especially in the hydrodynamic entrance region. Due to its relevance, the aim of this research is to present a mathematical study to predict natural gas flow in cylindrical pipes with elliptic cross section in the hydrodynamic entrance region. The results in terms of different flow parameters and velocity and pressure distributions inside the pipes with different aspect ratios are presented and discussed.

In Partial Fulfillment of the Requirements for the Degree of

Abstract: ................................................................................................................................... ii Dedication................................................................................................................................ iv Acknowledgments.................................................................................................................... v Vita........................................................................................................................................... vii List of Tables............................................................................................................................. xii List of Figures............................................................................................................................ xiv Chapter 1 ‐ Introduction........................................................................................................... 1 1.1 ‐ Microbial fuel cells.................................................................................................. 2 1.2 ‐ Microbial fuel cell applications............................................................................... 4 1.3 ‐ Research problems associated with MFC technology............................................. 5 1.4 ‐ Introduction to this research study......................................................................... 6 Chapter 2 ‐ Effects of Nano‐structure Enhanced Cathodes on Electricity Production of Two‐ Chamber Microbial Fuel Cells 2.1 ‐ Introduction............................................................................................................ 8 2.2 ‐ Materials and Methods........................................................................................... 16 2.2.1 ‐ Electrode construction Graphite bar anodes.......................................................................................... 18 Graphite bar cathodes....................................................................................... 20

Use of low-cost biopolymers and biopolymeric composite systems for heavy metal removal from water

Abstract: The quality and quantity of freshwater resources are declining because of the pressures associated with human population increase. Heavy metals are among the most persistent and non-biodegradable pollutants associated with industrial discharges, mining activities and agricultural activities. However, a practical and affordable solution to the efficacious removal of heavy metals from wastewater prior to discharge into aquatic environments has yet to be implemented. Therefore, intensive research continues to address the sustainable use of materials from agricultural or industrial by-products in wastewater treatment. This review summarizes the properties of low-cost biopolymeric composite systems (including chitosan and hemicellulose) for the removal of heavy metals from aquatic systems. The materials presented in this review come from agricultural or industrial by-products which provide a twofold benefit of not only providing a means of treating water but also an effective method of utilization of these by-products which otherwise form an additional waste-stream.