Estudo experimental sobre o comportamento do escoamento bifásico água - ar para a medição de vazão em placa de orifício

The measurement of flow through the prediction of differential pressure is widely used in industrial day-to-day, this happens mainly due to the fact that it is used for various types of fluids, such as gas flow and liquid with viscosity distinct even flow of fluids with particles in suspension. The suitability of this equipment for measuring mass flow in two-phase flow is of paramount importance for technological development and reliability of results. When it comes to two-phase flow the relationship between the fluids and their interactions are of paramount importance in predicting the flow. In this paper, we propose the use of concentric orifice plate used in small diameter pipes of 25.4 mm order where a two-phase flow flows between water-air. The measurement of single-phase flow was made with the use of data in NBR 5167-1 which was used to Stolz equation for measuring discharge coefficient. In the two-phase flow was used two correlations widely used in the prognosis of mass flow, the pattern of Zhang (1992) and the model of Chisholm (1967), to the homogeneous flow model. It was observed that the behavior found in Zhang model are consistent more realistic way the mass flow of two-phase flow, since the model Chisholm extrapolate the parameters for the downstream pressure P2, the orifice plate, and the rated discharge coefficient. The use of the change in pressure drop P1-P2 and discharge coefficient, led to a better convergence of the values obtained for the two-phase air-water stream.

Fabricação e caracterização de um compósito hibrido com resíduo lignocelulósico

This work aims to manufacture and characterize a hybrid plastic composite with the matrix isophthalic polyester resin base and having as reinforcing glass fiber and the dry endocarp of coconut (Coco nucifera Linn) in the form of particles as filler. The composite was made industrially in Tecniplas Industry and Trade LTDA. in the form of plate, and was manufactured process made by the manual lamination (Hand Lay Up). From the plate they were prepared test specimens for testing density, water absorption, uniaxial traction in dry and wet states, and testing of bending, as well as studies on the behavior of the generated fractures, macroscopic and microscopic, in mechanical tests through. All tests were performed in order to find the most viable applications the hybrid composite manufactured. The tensile and bending tests were analyzed last tensile properties, elasticity and deformation module. After the studies, it is observed that the percentage moisture absorbed was 3.03%. The presence of moisture in the tensile test meant a decrease of 19.77% from last stand, and 5.26% in the elastic modulus. For bending tests gave an average value of 69.13 MPa flexural strength. The results show the application of hybrid composite studied in lightweight structures, indoors, which require low / medium performance traction demands, and which involve flexural requests.

Análise de confiabilidade de um moto-ventilador centrífugo: aplicação no sistema de pressurização de subestação industrial para garantia da segurança operacional na indústria petroquímica

The need of the oil industry to ensure the safety of the facilities, employees and the environment, not to mention the search for maximum efficiency of its facilities, makes it seeks to achieve a high level of excellence in all stages of its production processes in order to obtain the required quality of the final product. Know the reliability of equipment and what it stands for a system is of fundamental importance for ensuring the operational safety. The reliability analysis technique has been increasingly applied in the oil industry as fault prediction tool and undesirable events that can affect business continuity. It is an applied scientific methodology that involves knowledge in engineering and statistics to meet and or analyze the performance of components, equipment and systems in order to ensure that they perform their function without fail, for a period of time and under a specific condition. The results of reliability analyzes help in making decisions about the best maintenance strategy of petrochemical plants. Reliability analysis was applied on equipment (bike-centrifugal fan) between the period 2010-2014 at the Polo Petrobras Guamaré Industrial, situated in rural Guamaré municipality in the state of Rio Grande do Norte, where he collected data field, analyzed historical equipment and observing the behavior of faults and their impacts. The data were processed in commercial software reliability ReliaSoft BlockSim 9. The results were compared with a study conducted by the experts in the field in order to get the best maintenance strategy for the studied system. With the results obtained from the reliability analysis tools was possible to determine the availability of the centrifugal motor-fan and what will be its impact on the security of process units if it will fail. A new maintenance strategy was established to improve the reliability, availability, maintainability and decreased likelihood of Moto-Centrifugal Fan failures, it is a series of actions to promote the increased system reliability and consequent increase in cycle life of the asset. Thus, this strategy sets out preventive measures to reduce the probability of failure and mitigating aimed at minimizing the consequences.

Desempenho de uma lagoa de infiltração na absorção de cheias e na recarga de aquífero

A type of macro drainage solution widely used in urban areas with predomi-nance of closed catchments (basins without outlet) is the implementation of detention and infiltration reservoirs (DIR). This type of solution has the main function of storing surface runoff and to promote soil infiltration and, consequently, aquifer recharge. The practice is to avoid floods in the drainage basin low-lying areas. The catchment waterproofing reduces the distributed groundwater recharge in urban areas, as is the case of Natal city, RN. However, the advantage of DIR is to concentrate the runoff and to promote aquifer recharge to an amount that can surpass the distributed natu-ral recharge. In this paper, we proposed studying a small urban drainage catchment, named Experimental Mirassol Watershed (EMW) in Natal, RN, whose outlet is a DIR. The rainfall-runoff transformation processes, water accumulation in DIR and the pro-cess of infiltration and percolation in the soil profile until the free aquifer were mod-eled and, from rainfall event observations, water levels in DIR and free aquifer water level measurements, and also, parameter values determination, it is was enabled to calibrate and modeling these combined processes. The mathematical modeling was carried out from two numerical models. We used the rainfall-runoff model developed by RIGHETTO (2014), and besides, we developed a one-dimensional model to simu-late the soil infiltration, percolation, redistribution soil water and groundwater in a combined system to the reservoir water balance. Continuous simulation was run over a period of eighteen months in time intervals of one minute. The drainage basin was discretized in blocks units as well as street reaches and the soil profile in vertical cells of 2 cm deep to a total depth of 30 m. The generated hydrographs were transformed into inlet volumes to the DIR and then, it was carried out water balance in these time intervals, considering infiltration and percolation of water in the soil profile. As a re-sult, we get to evaluate the storage water process in DIR as well as the infiltration of water, redistribution into the soil and the groundwater aquifer recharge, in continuous temporal simulation. We found that the DIR has good performance to storage excess water drainage and to contribute to the local aquifer recharge process (Aquifer Dunas / Barreiras).

Os impactos na qualidade da água e do solo de um manancial tropical do semiárido devido ao uso e ocupação e evento de seca extrema

Human activities alter soil features, causing the deterioration of its quality. Land use and occupation in drainage basins of water supply reservoirs can change the environmental soil quality and, thus, lead to the expansion of the soil potential of being a diffuse pollution source. In the Brazilian semiarid region, the soils are generally shallow with high susceptibility to erosion, favoring the sediment and nutrients input into the superficial waterbodies, contributing to the eutrophication process. Moreover, this region has high temperatures and high evapotranspiration rates, that are generally higher than the precipitation rates, causing a negative hydric balance and big volume losses by evaporation. The water volume reduction increases the nutrients’ concentration and, therefore, exacerbates the eutrophication process, deteriorating the water quality. Thereby, we hypothesized that the eutrophication process of semiarid reservoirs is intensified both by the extreme climatic events of prolonged drought, and by the diffuse pollution due to the basin land use and occupation. The study aimed to test whether the land use and occupation activities of the basin and the severe drought events intensify the eutrophication process of a semiarid tropical reservoir. To verify the influence of human activities carried out in the water supply of drainage basin on the soil quality and the eutrophication process, we conducted the mapping of the kind of use and occupation, as well the calculation of erosion for each activity and the soil quality evaluation of the riparian zone and water quality of the water supply. For the water analyses, the samplings were carried out monthly in the deeper point, near dam. For the soil, deformed composite samples were taken for the physical and chemical attributes analysis, according to the identified land use and occupation classes. The results showed that extreme droughts drastically reduces the water volume and elevates the nutrients concentration, contributing, thus, to a bigger degradation of water quality. Furthermore, we verified that human activities in the drainage basin promote the diffuse pollution, by increasing the soil susceptibility to erosion and nutrients contents. Summarizing, our results support the investigated hypothesis that activities of land use and occupation and extreme drought generate a combined effect that provide the intensification of eutrophication process of semiarid reservoirs.

Influência da pressão e da vazão de concentrado sobre o desempenho de ultrafiltração no pós-tratamento de esgotos

Despite the numerous advantages resulting from the use of membrane filters technology, intrinsic limitations fouling process become relevant to its applicability. The control of operating conditions is an important tool to mitigate fouling and achieve good levels of efficiency. In this sense, the objective of this study was to investigate the effect of transmembrane pressure and concentrate flow in the performance of ultrafiltration, applied to the post-treatment of domestic sewage. The process was evaluated and optimized by varying the pressure (0.5 and 1.5 bar) and the concentrate flow (300 and 600 L/h), using a 22 factorial design, in order to investigate the effects on the permeate flow and quality of effluents generated at each operating condition. We evaluated the following quality indicators for permeate: pH, electrical conductivity, total suspended solids, turbidity, calcium and Chemical Oxygen Demand (COD). In all tests, we observed marked reduction in the permeate flux at the early stages, followed by a slow decline that lasted until it reaches a relatively constant level, around 120 minutes of filtration. The increased pressure resulted in a higher initial permeate flux, but the decrease of the flow with time is greater for tests at higher pressure, indicating a more pronounced fouling process. On the other hand, increasing the concentrate flow resulted in a slower decline in permeate flux with the filtration time. Regarding the quality of permeate, the transmembrane pressure of 0,5 bar was the one that allowed better results, and was statistically confirmed through the two-way ANOVA test with repeated measures, significant effect of pressure on the turbidity of the permeate. The concentrate flow, in turn, showed no significant influence on any of the quality parameters. Thus, we conclude that, from an economic and environmental point of view, it is more interesting to operate ultrafiltration membrane system with a lower concentrate flow associated with a low transmembrane pressure, since under these conditions will produce less waste, and the permeate will present lower concentrations of the analyzed constituent, especially lower turbidity.

Avaliação do desempenho de argamassas à base de cimento Portland para rejuntamento de placas cerâmicas tipo II com adição de pó de borracha de pneus

In this work it is assessed the performance of Portland cement-based mortar to the grouting of type II ceramic plates with the addition of unusable tire rubber powder. It is presented a bibliographical review about the subject in which is done the theoretical and methodological foundation of the whole investigative process. The analyzed universe comprises a sample of mortar to the grouting of conventional ceramic plates type II (reference sample) and five more samples to the grouting of ceramic plates type II, which were made up of the addition of unusable tire rubber powder in the respective proportion (in mass) of 4%, 8%, 12%, 16% and 20%. These mortar samples were subject to the trials of determination of the consistency index (Brazilian Standard NBR 13276:2005), water retention ( Brazilian Standard NBR 14992 Attachment B:2003), permeability in 240 minutes (Brazilian Standard NBR 14992 Attachment G:2003), absorption of water by immersion (Brazilian Standard NBR 9781:2013), resistance to compression (Brazilian Standard NBR14992 Attachment D: 2003), resistance to traction in the flexion (Brazilian Standard NBR 13279:2005), resistance of traction adherence (Brazilian Standard NBR 14081 part 4:2012) and hardened mass density (Brazilian Standard NBR 13280: 2005). It has been found out from the analyzes of the results in the trial the following situation: the reference mortar used met the established requirements in the norms of specifications corresponding to only six from the eight parameters assessed in the research; the mortar with addition of 4,0% of tire rubber powder met the established requirements corresponding to only the resistance to compression and the resistance of adherence to traction. Thus, the other kinds of mortar with addition of 8,0 %, 12,0 %, 16,0 % and 20,0 % of tire rubber powder met the requirements of specifications corresponding to only the resistance to compression and the resistance of adherence to traction. This result concludes that the adding of tire rubber powder does not grant improvement to the mortar of type II grouting to the laying of ceramic plates.

Avaliação do desempenho de argamassas à base de cimento Portland para rejuntamento de placas cerâmicas tipo II com adição de pó de borracha de pneus

In this work it is assessed the performance of Portland cement-based mortar to the grouting of type II ceramic plates with the addition of unusable tire rubber powder. It is presented a bibliographical review about the subject in which is done the theoretical and methodological foundation of the whole investigative process. The analyzed universe comprises a sample of mortar to the grouting of conventional ceramic plates type II (reference sample) and five more samples to the grouting of ceramic plates type II, which were made up of the addition of unusable tire rubber powder in the respective proportion (in mass) of 4%, 8%, 12%, 16% and 20%. These mortar samples were subject to the trials of determination of the consistency index (Brazilian Standard NBR 13276:2005), water retention ( Brazilian Standard NBR 14992 Attachment B:2003), permeability in 240 minutes (Brazilian Standard NBR 14992 Attachment G:2003), absorption of water by immersion (Brazilian Standard NBR 9781:2013), resistance to compression (Brazilian Standard NBR14992 Attachment D: 2003), resistance to traction in the flexion (Brazilian Standard NBR 13279:2005), resistance of traction adherence (Brazilian Standard NBR 14081 part 4:2012) and hardened mass density (Brazilian Standard NBR 13280: 2005). It has been found out from the analyzes of the results in the trial the following situation: the reference mortar used met the established requirements in the norms of specifications corresponding to only six from the eight parameters assessed in the research; the mortar with addition of 4,0% of tire rubber powder met the established requirements corresponding to only the resistance to compression and the resistance of adherence to traction. Thus, the other kinds of mortar with addition of 8,0 %, 12,0 %, 16,0 % and 20,0 % of tire rubber powder met the requirements of specifications corresponding to only the resistance to compression and the resistance of adherence to traction. This result concludes that the adding of tire rubber powder does not grant improvement to the mortar of type II grouting to the laying of ceramic plates.

Evoluções nas modelagens de substratos artificiais (metamateriais) com práticas experimentais em antenas de microfita

Esse trabalho tem como objetivo apresentar configurações de substratos dielétricos inovadores projetados e fabricados a partir de estruturas metamateriais. Para isso, são avaliados diversos fatores que podem influenciar no seu desempenho. A princípio, foi feito um levantamento bibliográfico a respeito dos temas, que estão relacionados com as pesquisas sobre: materiais dielétricos, metamateriais e interferometria óptica. São estudados, pesquisados e desenvolvidos dois projetos experimentais propostos, que comprovam a eficiência de métodos, para se alcançar a permeabilidade magnética negativa na formação de metamateriais. O primeiro projeto é a produção de uma nova estrutura, com u anel ressoador triangular equilateral (Split Equilateral Triangle Resonator - SETR). O segundo projeto: aplica os princípios da interferometria óptica, especialmente, com o interferômetro de Fabry-Perot. Técnicas para obtenção dos dispositivos que complementam a placa metamaterial como substrato foram pesquisadas na literatura e exemplificadas principalmente por meio de simulações e medições. Foram feitas comparações, simulações e medições de estruturas convencionais e especiais. As experiências se concentram nas evoluções e modelagens de substratos metamateriais com aplicações em antenas de microfita. As melhorias de alguns parâmetros de desempenho de antenas também são relatadas. As simulações das antenas foram feitas nos programas computacionais comerciais. Os resultados medidos foram obtidos com um analisador vetorial de redes da Rhode and Schwarz modelo ZVB 14.

Evoluções nas modelagens de substratos artificiais (metamateriais) com práticas experimentais em antenas de microfita

Esse trabalho tem como objetivo apresentar configurações de substratos dielétricos inovadores projetados e fabricados a partir de estruturas metamateriais. Para isso, são avaliados diversos fatores que podem influenciar no seu desempenho. A princípio, foi feito um levantamento bibliográfico a respeito dos temas, que estão relacionados com as pesquisas sobre: materiais dielétricos, metamateriais e interferometria óptica. São estudados, pesquisados e desenvolvidos dois projetos experimentais propostos, que comprovam a eficiência de métodos, para se alcançar a permeabilidade magnética negativa na formação de metamateriais. O primeiro projeto é a produção de uma nova estrutura, com u anel ressoador triangular equilateral (Split Equilateral Triangle Resonator - SETR). O segundo projeto: aplica os princípios da interferometria óptica, especialmente, com o interferômetro de Fabry-Perot. Técnicas para obtenção dos dispositivos que complementam a placa metamaterial como substrato foram pesquisadas na literatura e exemplificadas principalmente por meio de simulações e medições. Foram feitas comparações, simulações e medições de estruturas convencionais e especiais. As experiências se concentram nas evoluções e modelagens de substratos metamateriais com aplicações em antenas de microfita. As melhorias de alguns parâmetros de desempenho de antenas também são relatadas. As simulações das antenas foram feitas nos programas computacionais comerciais. Os resultados medidos foram obtidos com um analisador vetorial de redes da Rhode and Schwarz modelo ZVB 14.

Contribuições em escalonamento e análise de desempenho de redes WirelessHART

Wireless Communication is a trend in the industrial environment nowadays and on this trend, we can highlight the WirelessHART technology. In this situation, it is natural the search for new improvements in the technology and such improvements can be related directly to the routing and scheduling algorithms. In the present thesis, we present a literature review about the main specific solutions for Routing and scheduling for WirelessHART. The thesis also proposes a new scheduling algorithm called Flow Scheduling that intends to improve superframe utilization and flexibility aspects. For validation purposes, we develop a simulation module for the Network Simulator 3 (NS-3) that models aspects like positioning, signal attenuation and energy consumption and provides an link individual error configuration. The module also allows the creation of the scheduling superframe using the Flow and Han Algorithms. In order to validate the new algorithms, we execute a series of comparative tests and evaluate the algorithms performance for link allocation, delay and superframe occupation. In order to validate the physical layer of the simulation module, we statically configure the routing and scheduling aspects and perform reliability and energy consumption tests using various literature topologies and error probabilities.

Contribuições em escalonamento e análise de desempenho de redes WirelessHART

Wireless Communication is a trend in the industrial environment nowadays and on this trend, we can highlight the WirelessHART technology. In this situation, it is natural the search for new improvements in the technology and such improvements can be related directly to the routing and scheduling algorithms. In the present thesis, we present a literature review about the main specific solutions for Routing and scheduling for WirelessHART. The thesis also proposes a new scheduling algorithm called Flow Scheduling that intends to improve superframe utilization and flexibility aspects. For validation purposes, we develop a simulation module for the Network Simulator 3 (NS-3) that models aspects like positioning, signal attenuation and energy consumption and provides an link individual error configuration. The module also allows the creation of the scheduling superframe using the Flow and Han Algorithms. In order to validate the new algorithms, we execute a series of comparative tests and evaluate the algorithms performance for link allocation, delay and superframe occupation. In order to validate the physical layer of the simulation module, we statically configure the routing and scheduling aspects and perform reliability and energy consumption tests using various literature topologies and error probabilities.

Obtenção e caracterização de um eco-compósito à base de látex e bainha da palha do coqueiro para isolamento térmico e acústico

With the emergence of new technologies, has grown the need to use new materials, and this has intensified research on the collection and use of materials from renewable sources, is to reduce production costs and / or environmental impact. In this context, it was found that the sheath coconut straw, can be utilized as raw material for the production of a eco-composite that can be used as a thermal and acoustic insulator. After selected from the coconut sheaths were subjected to treatment with aqueous 2 % sodium hydroxide (NaOH). The composite study was produced with the sheath and coconut natural latex, with coconut sheath percentage in the proportions 15%, 25% and 35% of the total compound volume. Physical, thermal and acoustic properties of the composites were analyzed in order to obtain data on the use of viability as thermoacoustic insulation. The CP15 composites, CP25 and CP35 showed thermal conductivity 0.188 W/m.K, 0.155 W/m.K and 0.150 W/m.K, respectively. It can be applied as thermal insulation in hot systems to 200 ° C. The CP35 composite was more efficient as a thermal and acoustic insulation, providing 20% noise reduction, 31% and 34% for frequencies of 1 kHz, 2 kHz and 4 kHz, respectively. The analyzes were based on ABNT, ASTM, UL. Based on these results, it can be concluded that the eco-composite produced the hem of coconut can be used as thermal and acoustic insulation. Thus, it gives a more noble end to this material, which most often is burned or disposed of improperly in the environment.

Obtenção e caracterização de um eco-compósito à base de látex e bainha da palha do coqueiro para isolamento térmico e acústico

With the emergence of new technologies, has grown the need to use new materials, and this has intensified research on the collection and use of materials from renewable sources, is to reduce production costs and / or environmental impact. In this context, it was found that the sheath coconut straw, can be utilized as raw material for the production of a eco-composite that can be used as a thermal and acoustic insulator. After selected from the coconut sheaths were subjected to treatment with aqueous 2 % sodium hydroxide (NaOH). The composite study was produced with the sheath and coconut natural latex, with coconut sheath percentage in the proportions 15%, 25% and 35% of the total compound volume. Physical, thermal and acoustic properties of the composites were analyzed in order to obtain data on the use of viability as thermoacoustic insulation. The CP15 composites, CP25 and CP35 showed thermal conductivity 0.188 W/m.K, 0.155 W/m.K and 0.150 W/m.K, respectively. It can be applied as thermal insulation in hot systems to 200 ° C. The CP35 composite was more efficient as a thermal and acoustic insulation, providing 20% noise reduction, 31% and 34% for frequencies of 1 kHz, 2 kHz and 4 kHz, respectively. The analyzes were based on ABNT, ASTM, UL. Based on these results, it can be concluded that the eco-composite produced the hem of coconut can be used as thermal and acoustic insulation. Thus, it gives a more noble end to this material, which most often is burned or disposed of improperly in the environment.

Metodologia para análise da dependabilidade de Smart Grids

Smart Grids are a new trend of electric power distribution, the future of current systems. These networks are continually being introduced in order to improve the reliability of systems, providing alternatives to energy supply and cost savings. Faced with increasing electric power grids complexity, the energy demand and the introduction of alternative sources to energy generation, all components of system require a fully integration in order to achieve high reliability and availability levels (dependability). The systematization of a Smart Grid from the Fault Tree formalism enable the quantitative evaluation of dependability of a specific scenario. In this work, a methodology for dependability evaluation of Smart Grids is proposed. A study of case is described in order to validate the proposal. With the use of this methodology, it is possible to estimate during the early design phase the reliability, availability of Smart Grid beyond to identify the critical points from the failure and repair distributions of components.