Velocity Fluctuation
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. 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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2. MODELING AND ANALYSIS OF UNSTEADY FLOW BEHAVIOR IN DEEPWATER CONTROLLED MUD-CAP DRILLING
Abstract A new mathematical model was developed in this study to simulate the unsteady flow in controlled mud-cap drilling systems. The model can predict the time-dependent flow inside the drill string and annulus after a circulation break. This model consists of the continuity and momentum equations solved using the explicit Euler method. The model consider
Braz. J. Chem. Eng.. Publicado em: 2016-03
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3. Identification of defluidization region in a gas-solid fluidized bed using a method based on pressure fluctuation measurements
Industrial applications that involve fluidized bed operations must prevent the undesirable phenomenon of partial or complete bed defluidization. Defluidization can be avoided by increasing the gas velocity and/or, in some cases, changing the solid feed conditions in the system, provided that the changes in the hydrodynamics of the flow are detected early eno
Brazilian Journal of Chemical Engineering. Publicado em: 2009-09
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4. Efeitos de superfície nas propriedades térmicas e dinâmicas de filmes de cristais líquidos esméticos. / Surface effects on the thermal and dynamical proprieties of smectic liquid crystal filmes.
The thermal and dynamical properties of free-standing films are strongly dependent on the boundary conditions and the presence of an external field. Using distinct theoretical models and the dynamic light scattering experimental setup, we study the surface and external field effects on the relaxation dynamics, fluctuation-induced interaction energy, and phas
Publicado em: 2007
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5. Modelo matemático para análise dos efeitos da turbulência em escoamentos bifásicos fluido - partícula / Mathematical model for turbulence effect analysis in two-phase flow type fluid-particle
Neste trabalho é analisado o efeito das partículas ou gotas, as quais constituem a fase dispersa, na turbulência da fase contínua (gás ou líquido). Este tipo de análise, a qual é conhecida como modulação da turbulência, busca obter as variações nos termos fontes de geração de energia cinética provocadas pela interação das partículas com o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2006
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6. Modelo matemático para análise dos efeitos da turbulência em escoamentos bifásicos fluido - partícula / Mathematical model for turbulence effect analysis in two-phase flow type fluid-particle
In this work the effect of particles or drops, which constitute the dispersed phase, is analyzed in the turbulence of the continuous phase (gas or liquid). This type of analysis, which is known as turbulence modulation, searchs to get the variations in the terms sources of generation of kinetic energy provoked by the interaction of particles with the continu
Publicado em: 2006
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7. Modelo matemático para análise dos efeitos da turbulência em escoamentos bifásicos fluido - partícula / Mathematical model for turbulence effect analysis in two-phase flow type fluid-particle
Neste trabalho é analisado o efeito das partículas ou gotas, as quais constituem a fase dispersa, na turbulência da fase contínua (gás ou líquido). Este tipo de análise, a qual é conhecida como modulação da turbulência, busca obter as variações nos termos fontes de geração de energia cinética provocadas pela interação das partículas com o
Publicado em: 2006
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8. Identificação e monitoramento de regime fluidodinamico em leitos fluidizados gas-solido
Power spectra obtained through Fast Fourier Transform (FTT) from time series of pressure fluctuation, showed to be an effective technique for on line monitoring of typical fluidization regimes of gas-solid bubbling columns. It was experimentally verified that the methodology permitted the identification and distinction of different contact regimes. This meth
Publicado em: 2004
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9. An experimental investigation of the effects of nozzle ellipticity on the flow structure of co-flow jet diffusion flames
The flow structure of cold and ignited jets issuing into a co-flowing air stream was experimentally studied using a laser Doppler velocimeter. Methane was employed as the jet fluid discharging from circular and elliptic nozzles with aspect ratios varying from 1.29 to 1.60. The diameter of the circular nozzle was 4.6 mm and the elliptic nozzles had approximat
Journal of the Brazilian Society of Mechanical Sciences. Publicado em: 2001
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10. Effect of different surface roughnesses on a turbulent boundary layer
The classical treatment of rough wall turbulent boundary layers consists in determining the effect the roughness has on the mean velocity profile. This effect is usually described in terms of the roughness function delta U+. The general implication is that different roughness geometries with the same delta U+ will have similar turbulence characteristics, at
Journal of the Brazilian Society of Mechanical Sciences. Publicado em: 2000
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11. Introdução de um novo marcador laboratorial de atividade inflamatoria associada a infecção
Clinical and experimental evidence have demonstrated that proinflammatory interleukines (TNF-?, IL-1,IL-6, IL-8) are the most important mediators in the pathogenesis of the Sepsis Syndrome. They lead to the fluctuation of the white blood cells, a rise in the acute phase proteins as CRP, and of consequence, the alteration in the viscosity of the blood leading
Publicado em: 1999
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12. Rhythmic Differences in the Basipetal Movement of Indoleacetic Acid between Separated Upper and Lower Halves of Geotropically Stimulated Corn Coleoptiles 1
Rhythmic fluctuation in the basipetal movement of auxin occurs in corn (Zea mays) coleoptiles oriented either in the vertical or in the horizontal position. This periodicity of transport rate varies from region to region in a horizontal coleoptile. Between an upper and lower half coleoptile (with respect to gravity), the comparable regions in the coleoptile