André Luiz Amarante Mesquita

Decision support system for micro-hydro power plants in the Amazon region under a sustainable development perspective

One of the main obstacles to the socio-economic development of the Brazilian Amazon is the lack of electric energy in the numerous small isolated communities of the region that hampers value-added agricultural production, revenue growth and creation of jobs. One way to solve this problem is by setting up micro-hydro power (MHP) plants under a sustainable development perspective. This paper presents a decision support system (DSS) that analyzes this solution. The system considers the hydrological, topographical, geotechnical, environmental, energy, economic and social aspects of the target site. A detailed analysis is made of the hydrological model that employs a rainfall run-off model for small catchment analysis; the energy planning favors a two-turbine method to determine the maximum energy production during demand peaks, and the economic aspects show that the costs of energy generated by MHP plants are comparable to those from rural grid systems and lower than those from from diesel generators. Thus, the use of the hydro-power resources of the small catchments of Amazonia combined with the minimization of the environmental impacts caused by MHP not only fulfills the energy demand of the small communities of region, but is also viable economically along with job creation and revenue generation, and it supports the perspective of sustainable development.

A water flow pattern analysis of Guajará Bay: Amazon Estuary - Brazil

This work describes the steps required to construct a hydrodynamic model of the Guajara Bay, using Geographic Information Systems and the Finite Element Method. An overview of the problem that motivates this modelling procedure, i.e., the pollutant dispersion, is presented. The computer software used is then discussed, stressing the links between the data model entities. The calibration procedure is described. The methods used to obtain field data and the results obtained are presented, alongside the main flow patterns of the water. The simulations and applications of the model are discussed at the end of the paper.

An Improved Approach for Performance Prediction of HAWT Using the Strip Theory

This work reviews briefly the basis of the strip theory or Blade Element/Momentum method and its most used approaches for design and performance prediction of Horizontal-Axis Wind Turbines – HAWT, and proposes a new improved approach for the whole extension of the Tip Speed Ratio – TSR region. The results are compared to others found in the literature and to available experimental data. It is concluded that the proposed model provides similar results to the compared models to regions of TSR greater than 2, as is the case of the electricity-generating fast-running turbines, and extends the validity of these methods to regions of TSR smaller than 2, generally the case of multi-bladed HAWT employed for water pumping.

An Investigation of a Mathematical Model for the Internal Velocity Profile of Conical Diffusers Applied to DAWTs

The Diffuser Augmented Wind Turbines (DAWTs) have been widely studied, since the diffusers improve the power coefficient of the wind turbine, particularly of small systems. The diffuser is a device which has the function of causing an increase on the flow velocity through the wind rotor plane due to pressure drop downstream, therefore resulting in an increase of the rotor power coefficient. This technology aids the turbine to exceed the Betz limit, which states that the maximum kinetic energy extracted from the flow is 59.26%. Thus, the present study proposes a mathematical model describing the behavior of the internal velocity for three conical diffusers, taking into account the characteristics of flow around them. The proposed model is based on the Biot-Savarts Law, in which the vortex filament induces a velocity field at an arbitrary point on the axis of symmetry of the diffusers. The results are compared with experimental data obtained for the three diffusers, and present good agreement.

Gas-Solid Flow Applications for Powder Handling in Industrial Furnaces Operations

Gas-solid flow occurs in many industrial furnaces operations. The majority of chemical engineering units operations, such as drying, separation, adsorption, pneumatic conveying, fluidization and filtration involve gas-solid flow. Poor powder handling in an industrial furnace operation may result in a bad furnace performance, causing errors in the mass balance, erosion caused by particles impacts in the pipelines, attrition and elutriation of fines overloading the bag houses. The lack of a good gas-solid flow rate measurement can cause economic and environmental problem due to airborne. The chapter is focused on the applications of powder handling related with furnaces of the aluminum smelters processes such as anode baking furnace and electrolytic furnace (cell) to produce primary aluminum. The anode baking furnace illustrated in figure 1 is composed by sections made up of six cells separated by partitions flue walls through which the furnace is fired to bake the anodes. The cell is about four meters deep and accommodates four layers of three anode blocks, around which petroleum coke is packed to avoid air oxidation and facilitate the heat transfer. During the baking process, the gases released are exhausted to the fume treatment center

Contribution to hydrological modelling of small Amazonian catchments: application of rainfall–runoff models to simulate flow duration curves

Abstract The objective of this study is to analyse three rainfall–runoff hydrological models applied in two small catchments in the Amazon region to simulate flow duration curves (FDCs). The simple linear model (SLM) considers the rainfall–runoff process as an input–output time-invariant system. However, the rainfall–runoff process is nonlinear; thus, a modification is applied to the SLM based on the residual relationship between the simulated and observed discharges, generating the modified linear model (MLM). In the third model (SVM), the nonlinearity due to infiltration and evapotranspiration is incorporated into the system through the sigmoid variable gain factor. The performance criteria adopted were a distance metric (δ) and the Nash-Sutcliffe coefficient (R2) determined between simulated and observed flows. The good results of the models, mainly the MLM and SVM, showed that they could be applied to simulate FDCs in small catchments in the Amazon region. Editor D. Koutsoyiannis; Associate editor A. Montanari Citation Blanco, C.J.C., Santos, S.S.M., Quintas, M.C., Vinagre, M.V.A., and Mesquita, A.L.A., 2013. Contribution to hydrological modelling of small Amazonian catchments: application of rainfall–runoff models to simulate flow duration curves. Hydrological Sciences Journal, 58 (7), 1–11.

Experimental analysis of the flow between stay and guide vanes of a pump-turbine in pumping mode

An experimental study was conducted in a pump-turbine model in pumping mode, in order to characterize the flow field structure in the region between stay and guide vanes, using mainly the laser-Doppler anemometry in a two-color and back-scattered light-based system. The structure of the steady and unsteady flow was analyzed. The measurements were performed at three operation points. The obtained data provide appropriate boundary conditions and a good base of validation for numerical codes, and for the understanding of main loss mechanisms of this complex flow.

Contribution to the marine propeller hydrodynamic design for small boats in the Amazon region

Na Amazonia, a navegacao e muito importante devido a extensao de rios navegaveis e a falta de redes rodoviarias alternativas. As embarcacoes geralmente trabalham em condicoes desfavoraveis, uma vez que nao ha relacao entre a hidrodinâmica dos helices, geometria e as dimensoes do casco da embarcacao. Atualmente, nao ha metodologia para otimizacao hidrodinâmica com baixo custo computacional e facil implementacao na regiao. O objetivo deste trabalho foi o desenvolvimento de uma abordagem matematica voltada para o projeto de propulsores maritimos aplicados as embarcacoes tipicamente encontradas nos rios da Amazonia. Nos desenvolvemos uma formulacao otimizada para o calculo das distribuicoes de corda e ângulo de torcao, considerando o modelo classico de Glauert. Uma analise teorica para as relacoes de empuxo e torque em um volume de controle anular foi realizado. O modelo matematico utilizado foi baseado na teoria do momento do elemento de pa (BEMT). Concluimos que a nova metodologia, proposta neste trabalho, demonstra bom comportamento fisico quando comparado com a teoria de Glauert e os dados experimentais do propulsor Wageningen B3-50.

High CO2 effects on growth and biometal contents in the pioneer species Senna reticulata: climate change predictions

The aim of the present study consisted in evaluating the effects of CO2 enrichment on the growth and biometal/nutrient content and accumulation in Senna reticulata germinated under two different carbon dioxide concentrations: atmospheric (360 mg L-1) and elevated (720 mg L-1). Biometal/nutrient determinations were performed on three different plant portions (leaflets, stem and root) using flame atomic absorption spectrometry. In general, the biometal and nutrient stoichiometries in roots were increased, probably due to reduced transpiration, and consequent biometal accumulation. An Artifical Neural Network analysis suggests that Mg, Na and Fe display the most different behavior when comparing plants germinated at atmospheric and elevated CO2 conditions. Biomass and growth increases and certain elemental levels indicate that S. reticulata benefits from increased CO2 levels, however some results indicate the contrary, making further studies in this context necessary, as these changes may lead to direct effects on food safety, crop yields, and phytoremediation efficiency.

Gas-Solid Flow Applications for Powder Handling in Aluminum Smelters Processes

Gas-solid flow occurs in many industrial furnace processes. The majority of chemical engineering unit operations, such as drying, separation, adsorption, pneumatic conveying, fluidization and filtration involve gas-solid flow.