Shear Flows
Mostrando 1-12 de 51 artigos, teses e dissertações.
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1. Experimental bedforms by saline density currents
Abstract Bedforms are sedimentary features that can be generated on the seafloor by the interaction between density currents and mobile beds. Developing knowledge about the hydraulic and sedimentary processes involved during these events is in the interest of research groups and oil companies. Because of the magnitude of the density currents in its natural e
Braz. J. Geol.. Publicado em: 20/05/2019
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2. A Statistical Dynamic Model for the Turbulent Transport of Kinetic Energy in Shear Layers
ABSTRACT: Dynamic statistical equations for the turbulent fluxes of scalars and momentum in incompressible flows are derived after time wise integration of the equation for the oscillating transported property, decomposing the turbulent fluxes in terms representing distinct features of the main and fluctuating flow that influence the respective turbulent tra
J. Aerosp. Technol. Manag.. Publicado em: 07/06/2018
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3. Direct Numerical Simulation Code Validation for Compressible Shear Flows Using Linear Stability Theory
ABSTRACT: In order to simulate compressible shear flow stability and aeroacoustic problems, a numerical code must be able to capture how a baseflow behaves when submitted to small disturbances. If the disturbances are amplified, the flow is unstable. The linear stability theory (LST) provides a framework to obtain information about the growth rate in relatio
J. Aerosp. Technol. Manag.. Publicado em: 07/05/2018
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4. Wall function treatment for bubbly boundary layers at low void fractions
Abstract The present work investigates the role of different treatments of the lower boundary condition on the numerical prediction of bubbly flows. Two different wall function formulations are tested against experimental data obtained for bubbly boundary layers: (i) a new analytical solution derived through asymptotic techniques and (ii) the previous formul
An. Acad. Bras. Ciênc.. Publicado em: 2018-03
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5. 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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6. NUMERICAL RESEARCH ON THE THREE-DIMENSIONAL FIBER ORIENTATION DISTRIBUTION IN PLANAR SUSPENSION FLOWS
Abstract To describe flow-induced fiber orientation, the Fokker-Planck equation is widely applied in the processing of composites and fiber suspensions. The analytical solution only exists when the Péclet number is infinite. So developing a numerical method covering a full range of Péclet number is of great significance. To accurately solve the Fokker-Plan
Braz. J. Chem. Eng.. Publicado em: 2017-01
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7. SELF-SIMILARITY OF VERTICAL BUBBLY JETS
AbstractAn integral model for vertical bubbly jets with nearly monodisperse bubble sizes is presented. The model is based on the Gaussian type self-similarity of mean liquid velocity, bubble velocity and void fraction, as well as on functional relationships for initial liquid jet velocity and radius, bubble diameter and relative velocity. Adjusting the model
Braz. J. Chem. Eng.. Publicado em: 2015-06
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8. Influência da geometria da nanocarga na estruturação, orientação e propriedades de filmes tubulares de nanocompósitos de PA6 / Influence of the nanoparticles shape on the structure, orientation and properties of pa6 nanocomposites blown films
The structure and morphology of polymers and consequently their properties are dependent on the processing conditions. During the blown film process, high shear and elongational flows can induce a preferred orientation of the polymer chains; controlling the process conditions, it is possible to obtain films with anisotropic properties. Polymeric nanocomposit
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/06/2012
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9. On the evaluation of linear and non-linear models using DNS data of turbulent channel flows
In this paper, a priori and a posteriori analyses of algebraic linear and non-linear models are carried out in order to compare their ability to predict near wall turbulent flows. Tests were done using data from a direct numerical simulation (DNS) of a plane channel flow for three Reynolds numbers, based on the friction velocity, Reτ = 180, Reτ = 395 and R
J. Braz. Soc. Mech. Sci. & Eng.. Publicado em: 2012-12
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10. Observação do transporte de sedimentos em suspensão ao longo do Canal Norte do rio Amazonas durante condições de baixa descarga (outubro 2008) / Observation of suspended sediment transport along North Channel of Amazon river during low discharge (October 2008)
The Amazon river, located in northernBrazil, discharges between 80,000 and 250,000 m3s-1 of water onto the adjacent shelf, creating a plume of brackish water that extends hundreds of kilometers away from the river mouth. This river also carries a large amount of fine sediments to the ocean where fluid mud has been found in the topset and upper foreset layers
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/10/2011
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11. Resolução numérica de escoamentos compressíveis empregando um método de partículas livre de malhas e o processamento em paralelo (CUDA) / Numerical resolution of compressible flows employing a mesfree particle method and CUDA
Os métodos numéricos convencionais, baseados em malhas, têm sido amplamente aplicados na resolução de problemas da Dinâmica dos Fluidos Computacional. Entretanto, em problemas de escoamento de fluidos que envolvem superfícies livres, grandes explosões, grandes deformações, descontinuidades, ondas de choque etc., estes métodos podem apresentar algu
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/08/2011
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12. Nonlinear instabilities on a granular bed sheared by a turbulent liquid flow
The granular media is of great importance in our quotidian, and their transport by a fluid flow is frequently found in nature and in industry. When the shear stresses exerted by the fluid flow on a granular bed are bounded to some limits, a mobile granular layer known as bed-load takes place in which the grains stay in contact with the fixed part of the gran
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011-09