Turbulence
Mostrando 25-36 de 366 artigos, teses e dissertações.
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25. Influence of agitation intensity on flotation rate of apatite particles
Abstract The agitation intensity has a directly influence on flotation performance, lifting the particles and promoting the contact of bubbles and particles. In this paper, the energy input by the agitation on apatite flotation was investigated. The influence of pulp agitation in the flotation rate of particles with different sizes and two dosage levels was
REM, Int. Eng. J.. Publicado em: 2017-12
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26. Sonic anemometry and sediment traps to evaluate the effectiveness of windbreaks in preventing wind erosion
ABSTRACT The present work analyzes the effectiveness of windbreaks against wind erosion through the study of streamline patterns and turbulent flow by means of sonic anemometry and sediment traps. To this end, windbreaks composed of plastic meshes (7.5 m long and 0.7 m tall) were used. Windbreaks are a good means to reduce wind erosion, as they produce a pos
Sci. agric. (Piracicaba, Braz.). Publicado em: 2017-12
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27. Una mirada a la generación de la década de 1970 en Ecuador: Teoría del desencanto de Raúl Pérez Torres
Abstract: This article interprets the novel Teoría del desencanto by the Ecuadorian writer Raúl Pérez Torres. The purpose of this analysis is to know, by mean of a hermeneutic lecture in the way of Schlegel, some of the most important meanings suggests by the novel, focused on the generation of 1970s decade in Ecuador. Some of this meanings are: the quest
Let. Hoje. Publicado em: 2017-12
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28. CFD simulation of the mixing and dispersing of floating particles in a viscous system
Abstract Based on the Gidaspow model, the distributions of velocity, turbulence intensity, and solid concentration in stirred vessels equipped with a down-pumping propeller (TXL),a six flat-blade disc turbine (Rushton), or a down-pumping six 45° pitched-blade turbine (PBTD-6) in a viscous system were simulated. The power curve of the TXL propeller and the d
Braz. J. Chem. Eng.. Publicado em: 2017-10
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29. Aerodynamics of Harmonically Oscillating Aerofoil at Low Reynolds Number
ABSTRACT: Two-dimensional flows over harmonically oscillating symmetrical aerofoil at reduced frequency of 0.1 were investigated for a Reynolds number of 135,000, with focus on the unsteady aerodynamic forces, pressure and vortex dynamics at post-stall angles of attack. Numerical simulations using ANSYS® FLUENT CFD solver, validated by wind tunnel experimen
J. Aerosp. Technol. Manag.. Publicado em: 2017-03
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30. Numerical Analysis of Swirl Effects on Conical Diffuser Flows
ABSTRACT: The present paper focuses on the effect of swirl on important parameters of conical diffusers flows such as static pressure evolution, recirculation zones and wall shear stress. Governing equations are solved using a software based on the finite volume method. Moreover, turbulence effects are taken into account employing the k-ε RNG model with an
J. Aerosp. Technol. Manag.. Publicado em: 2017-03
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31. Seasonal variation in the reproductive activity of male goats raised under tropical climate conditions
ABSTRACT This study analyzed seasonal variations in the testes, the concentration of sex hormones, the parameters of fresh and thawed semen, and the sexual behavior of male Alpine goats from a temperate region in a tropical climate and possible interference with fertility. The maximum and minimum temperature and luminosity were recorded daily, while seminal,
R. Bras. Zootec.. Publicado em: 2017-03
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32. COMPUTATIONAL FLUID DYNAMICS (CFD) APPLICATION FOR VENTILATION STUDIES IN BROILER HOUSES
ABSTRACT With the recent increase in the number of acclimatized broiler houses in Brazil, design and adaptation of facilities to withstand the tropical weather conditions enabling the maintenance of ideal conditions without increasing costs have been major challenges. The aim of this study was to evaluate the ventilation system in solid-wall broiler houses u
Eng. Agríc.. Publicado em: 2017-02
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33. EXPERIMENTAL STUDY ON THE COLLABORATIVE DRAG REDUCTION PERFORMANCE OF A SURFACTANT SOLUTION IN GROOVED CHANNELS
Abstract Turbulence with a relatively larger vortex is obtained in drag-reducing surfactant solution, which provides an excellent condition for the application of small scale grooves. In this work, the coupling drag reduction performance of surfactant solution and grooves was experimentally investigated to explore the complementary possibility between their
Braz. J. Chem. Eng.. Publicado em: 2017-01
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34. Development of Three-Dimensional Electrodes of PbO2 Electrodeposited on Reticulated Vitreous Carbon for Organic Eletrooxidation
The application of electrochemical technology for the degradation of organic pollutants often faces two main problems, related to the anode material and mass transport limitations. Although PbO2 electrode is inexpensive and provides satisfactory electrooxidation kinetics, in the form of plane electrodes it is unable to resolve the mass transfer problem that
J. Braz. Chem. Soc.. Publicado em: 2017-01
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35. Numerical Study of Wake Characteristics in a Horizontal-Axis Hydrokinetic Turbine
ABSTRACT Over the years most studies on wake characteristics have been devoted to wind turbines, while few works are related to hydrokinetic turbines. Among studies applied to rivers, depth and width are important parameters for a suitable design. In this work, a numerical study of the wake in a horizontal-axis hydrokinetic turbine is performed, where the ma
An. Acad. Bras. Ciênc.. Publicado em: 01/12/2016
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36. Numerical Study of Reduced Frequency Effect on Longitudinal Stability Derivatives of Airfoil under Pitching and Plunging Oscillations
ABSTRACT In this study, incompressible, unsteady and turbulent flow over an airfoil with pitching and plunging oscillations is numerically studied in order to investigate the effect of reduced frequency on stability derivatives of oscillating airfoil. Linear k – ε model called Launder-Sharma and Rhie and Chow model are used for turbulence modeling and ove
J. Aerosp. Technol. Manag.. Publicado em: 2016-09