Isotropic Turbulence
Mostrando 1-12 de 18 artigos, teses e dissertações.
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1. 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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2. Estudo de estrutura turbulenta gerada por tanque de grade oscilante observada por PIV / Study design generated by turbulent tank grid oscillating observed by PIV
Um regime ou fluxo turbulento pode ser definido simplificadamente como uma forma de escoamento no qual o movimento de um fluido ocorre de forma aparentemente aleatória. A natureza caótica desse tipo de regime não possibilita que o problema seja abordado de modo determinístico, consequentemente, não pode ser descrito através de expressões analíticas p
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/06/2012
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3. Coherent vorticity extraction in 3D homogeneous isotropic turbulence: influence of the Reynolds number and geometrical statistics
The coherent vorticity extraction method (CVE) is based on the nonlinear filtering of the vorticity field projected onto an orthonormal wavelet basis made of compactly supported functions. CVE decomposes each turbulent flow realization into two orthogonal components: a coherent and an incoherent random flow. They both contribute to all scales in the inertial
Brazilian Journal of Physics. Publicado em: 2009-09
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4. ZIMORA - UM MODELO NUMÉRICO 3D DE DISPERSÃO ATMOSFÉRICA / ZIMORA - A 3D NUMERICAL MODEL FOR ATMOSPHERIC DISPERSION
In this thesis, we presents a development and validation of a 3D numerical model for the advection-diffusion equation. Models of this kind has been developed for scientific investigations and to support atmospheric emissions control and environmental policy decisions. To develop this model, we used the computational implementation of an explicit numerical sc
Publicado em: 2009
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5. UMA SOLUÇÃO PARA A EQUAÇÃO DA ENERGIA CINÉTICA TURBULENTA EMPREGANDO O MÉTODO DAS CARACTERÍSTICAS / A SOLUTION FOR THE TURBULENT KINETIC ENERGY EQUATION EMPLOYING THE METHOD OF CHARACTERISTICS
In this study, using the Method of Characteristics and numeric resources, presents a solution to the equation Spectral Density Evolution of Turbulent Kinetic Energy for a Convective Boundary Layer (CBL) in the morning. It presents three models for the evolution of spectral energy density. The first model, based on the assumption of a system of isotropic turb
Publicado em: 2009
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6. Uma solução analítica para a equação que descreve o decaimento da turbulência na camada limite convectiva : uma aproximação isotrópica / An analytical solution for the equation describing the decay of turbulence in the convective boundary layer : an isotropic approach
Nessa dissertação apresenta-se o desenvolvimento de um modelo espectral para o decaimento da turbulência na Camada Limite Convectiva (CLC). A equação dinâmica para o espectro de energia é obtida a partir das equações de Navier-Stokes [Rinze, 1975J, na qual o termo de produção de energia por efeito mecânico foi desprezado. Durante o período de tr
Publicado em: 2008
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7. Análise numérica do escoamento em uma sala retangular ventilada por um jato horizontal de parede
The present work investigates the three-dimensional turbulent airflow in a room ventilated by a horizontal wall jet. The geometry of Nielsen s experiment (Nielsen et al., 1978), for which experimental and numerical results for some turbulence models are available in the current literature, has been adopted in this work. This experiment consists of a rectangu
Publicado em: 2007
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8. Experiments and theory for two grids turbulence
Turbulence generated by a pair of oscillating grids in a water tank is investigated using the digital particle image velocimetry technique. Vertical and horizontal components of fluctuating velocities are measured. Experimental profiles of the turbulent kinetic energy k, and the energy dissipation rate, xi, obtained from the fluctuating velocities, are prese
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2006-06
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9. Fluxo de massa na interface ar-água em tanques de grades oscilantes e detalhes de escoamentos turbulentos isotrópicos / Gas transfer near the air-water interface in an oscillating-grid tanks and properties of isotropic turbulent flows
Gas transfer across the air-water interface in turbulent flows is an important process for many environmental systems. To improve the understanding of the basic principles involved in this phenomenon it is necessary to use suitable apparatus and experimental techniques. In this study, experiments and numerical simulation were conducted in a tank with one and
Publicado em: 2006
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10. Heat transfer in channels with solid and porous baffles.
This work focuses on the study of flow and heat transfer in a parallel plate channel with solid and porous baffles, in both laminar and turbulent regimes by using numerical simulations. The main concern is to validate results by using a unique set of equations (for porous, solid and clear domain) for channels with solid baffles, after that change solid to po
Publicado em: 2006
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11. MODELO ESPECTRAL DE HEISENBERG APLICADO AO DECAIMENTO DA TURBULÊNCIA NA CAMADA RESIDUAL / SPECTRAL MODEL DE HEISENBERG APPLIED TO THE DECLINE OF THE TURBULENCE IN RESIDUAL LAYER
In the study of the dispersion of contaminants in the atmosphere by computational simulations, the Eulerian approach, based in the diffusionadvection equation, is largely employed. In these simulations, concentration values are calculated at each point of a fixed grid in space and time and for this to be done it is necessary to determine an appropriated eddy
Publicado em: 2005
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12. Turbulent impinging jet into a porous bed.
This work focuses on the study of impinging jets actuating in both the presence and absence of a porous bed, in both laminar and turbulent regimes by using numerical simulations. Porous medium was treated as rigid, homogeneous and isotropic. The macroscopic transport equations are written for an elementary representative volume yielding a set of equation val
Publicado em: 2005