EE - Escola de Engenharia
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/512
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17 resultados
Resultados da Pesquisa
- ItemNumerical simulation of the resin transport through fiber reinforcement medium(SOUZA, Jeferson Avila; ROCHA, Luiz Alberto Oliveira; AMICO, Sandro Campos. Numerical simulation of the resin transport through fiber reinforcement medium. In: INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING – COBEM, 19., 2007, Brasília. Anais... Brasília: [s.n.], 2007. Disponível em: . Acesso em: 25 jul. 2015., 2007) Souza, Jeferson Avila; Rocha, Luiz Alberto Oliveira; Amico, Sandro CamposThis paper describes the numerical simulation of the RTM (Resin Transfer Molding) process applied to the modeling of the resin transport through a fibrous reinforcement. The molding volume which is to be impregnated with the resin is considered as a porous medium and the Darcy equation is used to determine the resin transport velocity through the mold. A control volume finite element method is used for the determination of the pressure gradients inside the mold and the resin flow front advance is obtained using a FAN technique. The finite volume method was built to be used with a bi-dimensional unstructured grid, hence allowing the discretization of complex geometries. In the simulation presented here, resin physical properties, like viscosity and density, and the permeability of the media were kept constants.
- ItemComputational modeling of a regular wave tank(2009) Gomes, Mateus das Neves; Olinto, Cláudio Rodrigues; Rocha, Luiz Alberto Oliveira; Souza, Jeferson Avila; Isoldi, Liércio AndréThis paper presents two different numerical methodologies to generate regular gravity waves in a wave tank. We performed numerical simulations of wave generation through the FLUENT® package, using the Volume of Fluid (VOF) multiphase model to reproduce the wave propagation in the tank. Thus it was possible to analyze two methods for generating regular waves that could be used in future work, especially in the study of devices of energy conversion from ocean waves into electrical energy.
- ItemModelagem computacional de um dispositivo do tipo coluna de água oscilante para a costa de Rio Grande(2009) Gomes, Mateus das Neves; Isoldi, Liércio André; Olinto, Cláudio Rodrigues; Rocha, Luiz Alberto Oliveira; Santos, Elizaldo Domingues dos; Souza, Jeferson AvilaEste trabalho apresenta a modelagem computacional de um conversor de energia das ondas do mar em energia elétrica do tipo Coluna de Água Oscilante (CAO) submetido ao clima de ondas da costa da cidade de Rio Grande. A simulação numérica foi realizada utilizando-se o pacote FLUENT® e empregando-se o modelo multifásico Volume of Fluid (VOF) na geração da onda e na interação da mesma com o conversor. O domínio computacional foi representado por um tanque de ondas acoplado ao dispositivo CAO, possibilitando analisar o seu comportamento quando sujeito a incidência de ondas regulares com características semelhantes ao clima de ondas na costa de Rio Grande. Os resultados obtidos demonstram a potencialidade da região em gerar energia elétrica a partir da energia das ondas do mar, através do conversor tipo CAO.
- ItemEnergia das ondas do mar: modelagem computacional de um dispositivo de galgamento(2009) Iahnke, Silvana Letícia Pires; Gomes, Mateus das Neves; Isoldi, Liércio André; Rocha, Luiz Alberto OliveiraEste trabalho apresenta um breve estudo sobre energia das ondas do mar bem como a modelagem computacional de um dispositivo do tipo galgamento. A simulação foi realizada através do software de Dinâmica dos Fluidos Computacional FLUENT®, tendo sido empregado o modelo multifásico Volume of Fluid (VOF), para representar adequadamente a interação entre água e ar. Os resultados obtidos foram satisfatórios, sendo, na geração da onda, a diferença máxima entre os resultados numéricos e a solução analítica, em torno de 4.6%. Foi observado também, que o conhecimento da altura da onda, aliado ao projeto adequado da rampa, são fatores que determinam a ocorrência do galgamento.
- ItemConstructal design applied to the optimization of heat transfer in a solid conducting wall(2007) Marques, Crístofer Hood; Santos, Elizaldo Domingues dos; Rocha, Luiz Alberto OliveiraThe present paper applies Constructal Design to optimize the geometry of a Yshaped negative fin that intrudes a solid conducting wall with heat generation. The main goal is the minimization of the thermal global resistance between the solid wall and the negative fin, which removes energy from the wall. The optimization is achieved by varying the angle between the tributary branch of the Y-Shaped fin and the horizontal axis, as well as, by varying the ratio between the volume of the fin and the rectangular volume that circumscribes it (ψ), while the other geometric parameters are maintained fixed. Constructal Design led to a best configuration, with a thermal global resistance of 53%, 49% and 48% for ψ = 0.3, ψ = 0.4 and ψ = 0.5, respectively, smaller than the ones for the worst configuration.
- ItemNumerical study of reservoir cooling by means of peltier effect(2008) Farias, Rodrigo Martins; Santos, Elizaldo Domingues dos; Isoldi, Liércio André; Rocha, Luiz Alberto OliveiraThe present work studies numerically and experimentally the water cooling process by means of natural convection inside a closed reservoir. The cooling process is performed by Peltier or Thermoelectric effect. The purpose here is to obtain the thermal gradient inside the reservoir and to search for the best point where the coldest water can be extracted from the reservoir, which can be considered a geometric optimization of the device thermal design. The analyzed flow is incompressible, laminar, transient and three-dimensional. The Boussinesq approximation is employed for the treatment of buoyancy forces. For the numerical approach of the flow, the mass, momentum and energy conservation equations are solved by a commercial package based on the finite volume method (FLUENT®). The temperature field as function of time obtained by numerical simulations is confronted with the experimental data. The numerical results estimated satisfactorily the transient thermal behavior predicted by laboratory experiments.
- ItemModelagem computacional de um dispositivo do tipo coluna de água oscilante para a costa de Rio Grande(2009) Gomes, Mateus das Neves; Isoldi, Liércio André; Olinto, Cláudio Rodrigues; Rocha, Luiz Alberto Oliveira; Santos, Elizaldo Domingues dos; Souza, Jeferson AvilaEste trabalho apresenta a modelagem computacional de um conversor de energia das ondas do mar em energia elétrica do tipo Coluna de Água Oscilante (CAO) submetido ao clima de ondas da costa da cidade de Rio Grande. A simulação numérica foi realizada utilizando-se o pacote FLUENT® e empregando-se o modelo multifásico Volume of Fluid (VOF) na geração da onda e na interação da mesma com o conversor. O domínio computacional foi representado por um tanque de ondas acoplado ao dispositivo CAO, possibilitando analisar o seu comportamento quando sujeito a incidência de ondas regulares com características semelhantes ao clima de ondas na costa de Rio Grande. Os resultados obtidos demonstram a potencialidade da região em gerar energia elétrica a partir da energia das ondas do mar, através do conversor tipo CAO.
- ItemConstructal design of solid state fermentation bioreactors(2009) Cunha, Daniele Colembergue da; Souza, Jeferson Avila; Costa, Jorge Alberto Vieira; Rocha, Luiz Alberto OliveiraConstructal Design is applied to geometric optimization of an insulated wall bioreactor. The optimization of the bioreactor geometry allows that it to operate, below a certain temperature limit, without external cooling equipment. The possibility of using less equipment shows how geometric optimization can be used as a tool for the ecologically correct management of energy. For the geometric optimization, a mathematical model that represents the solid state fermentation by Aspergillus niger is validated and used to study a column fixed bed bioreactor with fixed volume. The model is solved numerically for an insulated wall bioreactor. According to Constructal Design the shape of the bioreactor is free to change subject to volume constraint and in the pursuit of better performance. The optimal ratio between the diameter and the length of the bioreactor, i.e., the ratio which corresponds to the optimal maximum temperature equal to 35 ºC, is calculated for several inlet velocities, volumetric flow rates and inlet air temperatures.
- ItemHexahedral modular bioreactor for solid state bioprocesses(2009) Cunha, Daniele Colembergue da; Souza, Jeferson Avila; Rocha, Luiz Alberto Oliveira; Costa, Jorge Alberto VieiraThe design of a modular bioreactor for solid state fermentation is a promising development because it keeps the homogeneity of the bed at optimal levels. This study determines the optimum geometry of elementary modules of hexahedral bioreactors subjected to constant volume. The bioreactors have a square section and do not need an external cooling system, because the optimization limits the temperature of the bed to 35 C. The geometric optimization followed the Constructal principle of minimum heat resistance. The numerical simulations take into account the following parameters: inlet air temperature and velocity, and module volume. Once the elementary module has been selected, the total volume of the bioreactor can be calculated.
- ItemTwo-dimensional Control Volume Modeling of the Resin Transfer in a Porous Media with a Heterogeneous Permeability Tensor(2008) Souza, Jeferson Avila; Nava, Marcelo José Anghinoni; Rocha, Luiz Alberto Oliveira; Amico, Sandro CamposResin Transfer Molding (RTM) is a polymer composite processing technique widely used in the aeronautics and automotive sectors. This paper describes the numerical simulation of the RTM process where Darcy’s law was used for the mathematical formulation of the problem. A control volume finite element method was used for the determination of pressure gradients inside the mold, and a geometric reconstruction algorithm is used for the resin flow-front determination. Permeability of the medium was considered either a constant or a two dimensional tensor. The application was validated by direct comparison with literature data and good qualitative and quantitative agreement was obtained. The finite volume method was built to be used with a two-dimensional unstructured grid, hence allowing the analysis of complex geometries. The results showed that the proposed methodology is fully capable of predicting resin flow advancement in a multi-layer (with distinct physical properties) reinforced media.