EE - Escola de Engenharia
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/512
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9 resultados
Resultados da Pesquisa
- ItemNumerical analysis including pressure drop in oscillating water column device.(2015) Gomes, Mateus das Neves; Santos, Elizaldo Domingues dos; Isoldi, Liércio André; Rocha, Luiz Alberto OliveiraThe wave energy conversion into electricity has been increasingly studied in the last years. There are several proposed converters. Among them, the oscillatingwater column (OWC) device has been widespread evaluated in literature. In this context, the main goal of this work was to perform a comparison between two kinds of physical constraints in the chimney of the OWC device, aiming to represent numerically the pressure drop imposed by the turbine on the air flow inside the OWC. To do so, the conservation equations of mass,momentumand one equation for the transport of volumetric fraction were solved with the finite volume method (FVM). To tackle thewater-air interaction, the multiphase model volume of fluid (VOF)was used. Initially, an asymmetric constraint inserted in chimney duct was reproduced and investigated. Subsequently, a second strategywas proposed,where a symmetric physical constraint with an elliptical shapewas analyzed. Itwas thus possible to establish a strategy to reproduce the pressure drop in OWC devices caused by the presence of the turbine, as well as to generate its characteristic curve.
- ItemNumerical analysis of a regular wave over a vertical pile with a square section(2010) Teixeira, Paulo Roberto de Freitas; Gomes, Mateus das Neves; Santos, Elizaldo Domingues dos; Isoldi, Liércio André; Rocha, Luiz Alberto OliveiraThe study of the action of waves on piles is very important for the design of structures in coastal and oceanic areas. Currently, there is strong interest in analyzing the action of waves on piles with non-circular sections, such as rectangular or square ones. According to Vengatesan et al. (2000), the main reason for this interest is the low cost of the connections of the members in the structures with these sections. The objective of this paper is to analyze the action of a regular wave on a vertical pile with a square section employing two differents numerical methodologies for prediction of the wave fluid dynamic. To achieve this goal were used the FLUINCO and FLUENT® softwares. FLUINCO (Teixeira, 2001) employs a partitioned two-step semi-implicit Taylor-Galerkin method in the Navier-Stokes equations. The free surface is governed by its kinematic boundary condition and an arbitrary Lagrangian-Eulerian (ALE) formulation is used to enable movements of the free surface. The FLUENT® code (2006), version 6.3.26, implements a finite volume technique to solve the equation of continuity and the Navier-Stokes equations. The free surface is described by using the VOF method (Volume Of Fluid). The wave period of the studied problem is 4s and its height is 0.05 m. The pile is seated on the bottom and located in the center of a channel. The dimensions of the pile section are 1m × 1m and the channel is 30m long, 10m wide and 1m deep. This paper shows the results obtained by the models in terms of the velocity vectors, the deformation of the free surface and the drag force caused by the wave on the pile. The total horizontal force acting on the pile was analytically calculated using the Morison equation. It was observed very similar results to the numerical ones.
- ItemAnálise de malhas para geração numérica de ondas em tanques(2012) Gomes, Mateus das Neves; Isoldi, Liércio André; Santos, Elizaldo Domingues dos; Rocha, Luiz Alberto OliveiraEste trabalho apresenta uma metodologia para a geração numérica de ondas em tanques e também um estudo de malhas a serem utilizadas em simulações numéricas da propagação de ondas regulares bidimensionais em tanques. São testados dois tipos de geração e refinamento de malhas. Assim busca-se encontrar uma malha independente que forneça resultados com acurácia e com menor esforço computacional. Foram realizadas simulações numéricas da geração de ondas através do pacote FLUENT® , que é baseado no Método de Volumes Finitos (MVF). Foi empregado o modelo multifásico Volume of Fluid (VOF) para reproduzir a propagação da onda no tanque. Esses resultados poderão ser utilizados em trabalhos futuros, principalmente no estudo numérico de dispositivos para conversão de energia das ondas do mar em energia elétrica, como por exemplo, os dispositivos de coluna de água oscilante (OWC) e de galgamento.
- 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.
- ItemNumerical analysis of an oscillating water column converter considering a physical constraint in the chimney outlet(2014) Gomes, Mateus das Neves; Seibt, Flávio Medeiros; Rocha, Luiz Alberto Oliveira; Santos, Elizaldo Domingues dos; Isoldi, Liércio AndréThis work presents a 2D numerical study of an Oscillating Water Column (OWC) converter considering physical constraints in its outlet chimney to represent the turbine pressure drop. Two strategies were adopted. The first considers different dimensions for a physical constraint similar to an orifice plate, being the analysis performed in a laboratory scale. After that, other physical restriction with geometry similar to a rotor turbine was investigated in a real scale by means a dimensional variation. The numerical results indicate the importance of consider the pressure drop caused by turbine in the analysis of the OWC behavior.
- ItemNumerical analysis of the fluid-dynamic behavior of a submerged plate wave energy converter(2014) Seibt, Flávio Medeiros; Couto, Eduardo Costa; Teixeira, Paulo Roberto de Freitas; Santos, Elizaldo Domingues dos; Rocha, Luiz Alberto Oliveira; Isoldi, Liércio AndréThe need for clean and renewable energy sources has nowadays contributed to give relevance to the study of sea wave energy. In this context, the present work brings a computational modeling to analyze the fluid-dynamic behavior of a submerged plate wave energy converter. Basically, its operating principle consists in the passage of sea waves through a horizontal submerged plate, generating a flow under it where a turbine is placed, converting mechanical energy into electrical energy. The numerical model uses the software GAMBIT and FLUENT. In the latter, which is based on the finite volume method (FVM), the methodology used to represent the air−water interaction in the numerical simulations of the device is the multiphase volume of fluid (VOF) method. The objective of this paper is to analyze the influence of the opening ratio under the submerged plate with regard to its efficiency. To do so, the model, after verification and validation processes, was used in six simulations that differ from each other only in the vertical position of the plate in a wave tank. Results showed that a 5% increase in the opening ratio may produce an approximately 93% increase in the efficiency of the converter. In addition, a physical restriction was inserted under the plate, representing the pressure drop caused by a turbine, and other cases were simulated. These results indicate that a reduction of around 76% in the free region under the plate causes a decrease of only 5.5% in the submerged plate efficiency.
- ItemComputational modeling applied to the study of wave energy converters (WEC)(2014) Seibt, Flávio Medeiros; Letzow, Max; Gomes, Mateus das Neves; Souza, Jeferson Avila; Rocha, Luiz Alberto Oliveira; Santos, Elizaldo Domingues dos; Isoldi, Liércio AndréThe employment of numerical methods to solve engineering problems is a reality, as well as, the worldwide concern about the need of renewable and alternative energy sources. Thus, this work presents a computational model capable of simulating the operating principle of some Wave Energy Converters (WEC). To do so, the device is coupled in a wave tank, where the sea waves are reproduced. The Finite Volume Method (FVM) and the Volume of Fluid (VOF) model are adopted. The results showed that the converter's operating principle can be numerically reproduced, demonstrating the potential of computational modeling to study this subject.
- 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.
- ItemComputational modeling of an oscillating water column device for the Rio Grande coast(2009) Gomes, Mateus das Neves; Isoldi, Liércio André; Olinto, Cláudio Rodrigues; Rocha, Luiz Alberto Oliveira; Souza, Jeferson AvilaThis work presents the computational modeling of a converter of wave energy in electrical energy. The converter is Oscillating Water Column (OWC) type, submitted to the wave climate of Rio Grande city. The numerical simulation was performed using FLUE)T® package and employing the multiphase Volume of Fluid (VOF) model in the wave generation and in the interaction between the wave and the converter device. The computational domain was represented by a wave tank coupled with the OWC device. This domain allows the behavior analysis to be performed when the device is subjected to the incidence of regular waves. The waves were molded to represent the characteristics of the Rio Grande coastclimate. Results demonstrate that the OWC converter can be successfully used to convert the Rio Grande's coast wave energy in useful electrical energy.