Numerical Evaluation of Hydropneumatic Power for Two Oscillating Water Column (OWC) Devices Coupled Using Constructal Design

2017 ◽  
Author(s):  
Yuri Theodoro Barbosa de Lima ◽  
Luiz Alberto Oliveira Rocha ◽  
Mateus das Neves Gomes ◽  
Liércio André Isoldi ◽  
Elizaldo Domingues dos Santos
Keyword(s):  
Water Column ◽  
Numerical Evaluation ◽  
Oscillating Water Column ◽  
Constructal Design

scholarly journals Geometric Analysis through the Constructal Design of a Sea Wave Energy Converter with Several Coupled Hydropneumatic Chambers Considering the Oscillating Water Column Operating Principle

2021 ◽  
Vol 11 (18) ◽  
pp. 8630
Author(s):  
Yuri Theodoro Barbosa de Lima ◽  
Mateus das Neves Gomes ◽  
Liércio André Isoldi ◽  
Elizaldo Domingues dos Santos ◽  
Giulio Lorenzini ◽  
...  
Keyword(s):  
Water Column ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Wave Energy ◽  
Performance Indicator ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Constructal Design

The work presents a numerical study of a wave energy converter (WEC) device based on the oscillating water column (OWC) operating principle with a variation of one to five coupled chambers. The main objective is to evaluate the influence of the geometry and the number of coupled chambers to maximize the available hydropneumatic power converted in the energy extraction process. The results were analyzed using the data obtained for hydropneumatic power, pressure, mass flow rate, and the calculated performance indicator’s hydropneumatic power. The Constructal Design method associated with the Exhaustive Search optimization method was used to maximize the performance indicator and determine the optimized geometric configurations. The degrees of freedom analyzed were the ratios between the height and length of the hydropneumatic chambers. A wave tank represents the computational domain. The OWC device is positioned inside it, subject to the regular incident waves. Conservation equations of mass and momentum and one equation for the transport of the water volume fraction are solved with the finite volume method (FVM). The multiphase model volume of fluid (VOF) is used to tackle the water–air mixture. The analysis of the results took place by evaluating the performance indicator in each chamber separately and determining the accumulated power, which represents the sum of all the powers calculated in all chambers. The turbine was ignored, i.e., only the duct without it was analyzed. It was found that, among the cases examined, the device with five coupled chambers converts more energy than others and that there is an inflection point in the performance indicator, hydropneumatic power, as the value of the degree of freedom increases, characterizing a decrease in the value of the performance indicator. With the results of the hydropneumatic power, pressure, and mass flow rate, it was possible to determine a range of geometry values that maximizes the energy conversion, taking into account the cases of one to five coupled chambers and the individual influence of each one.

CONSTRUCTAL DESIGN APPLIED TO THE STUDY OF THE GEOMETRY AND SUBMERGENCE OF AN OSCILLATING WATER COLUMN

2015 ◽  
Vol 33 (2) ◽  
pp. 31-38 ◽  
Author(s):  
Giulio Lorenzini ◽  
Maria Lara ◽  
Luiz Rocha ◽  
Mateus Gomes ◽  
Elizaldo Santos ◽  
...  
Keyword(s):  
Water Column ◽  
Oscillating Water Column ◽  
Constructal Design

Analysis of Geometric Variation of Three Degrees of Freedom through the Constructal Design Method for a Oscillating Water Column Device with Double Hidropneumatic Chamber

2019 ◽  
Vol 396 ◽  
pp. 22-31
Author(s):  
Yuri T.B. Lima ◽  
Mateus das Neves Gomes ◽  
Camila F. Cardozo ◽  
Liércio André Isoldi ◽  
Elizaldo D. Santos ◽  
...  
Keyword(s):  
Water Column ◽  
Degrees Of Freedom ◽  
Numerical Study ◽  
Design Method ◽  
Geometric Optimization ◽  
Oscillating Water Column ◽  
Constructal Design ◽  
Wave Energy Converters ◽  
Volume Method ◽  
Geometric Variation

This paper presents a biphasic two-dimensional numerical study of sea wave energy converters with operating principle being Oscillating Water Column (CAO) devices with two couples chambers. For the study of the geometric optimization, the Constructal Design method is applied in association with the exhaustive search method to determine the geometric arrangement that leads to the greatest hydropneumatic power available. The objective function is the maximization of hydropneumatic power converted by the device. The constraints of the problem are the inflow volumes of the hydropneumatic chamber (VE1, VE2), the total volumes (VT1, VT2) and the thicknesses of the device columns (e1, e3). The degrees of freedom analyzed were H1/L1(ratio between height and length of the hydropneumatic chamber of the first device), H2/L2 (ratio between height and length of the hydropneumatic chamber of the second device), H2 (height of the column dividing the two devices) and e2 (thickness of the column dividing the devices). In the present work the degree of freedom H6 (depth of immersion of the device) is kept constant and equal to H6 = 9.86 m. The Finite Volume Method (FVM) was used in the numerical solution of the equations employed. For the treatment of the interaction between the air and water phases, the Volume of Fluid (VOF) method was applied. The results show that the maximum hydropneumatic power available was 5715.2 W obtained for degrees of freedom H1/L1 = H2/L2 = 0.2613 and e2 = 2.22 m. The case of lower performance has a power value equal to 4818.5 W with degrees of freedom equal to H1/L1 = H2/L2 = 0.2613 and e2 = 0.1 m.

Analysis of the Geometric Constraints Employed in Constructal Design for Oscillating Water Column Devices Submitted to the Wave Spectrum through a Numerical Approach

2019 ◽  
Vol 390 ◽  
pp. 193-210
Author(s):  
Mateus das Neves Gomes ◽  
Matheus José de Deus ◽  
Elizaldo Domingues dos Santos ◽  
Liércio André Isoldi
Keyword(s):  
Water Column ◽  
Wave Height ◽  
Significant Wave Height ◽  
Fluid Dynamic ◽  
Wave Spectrum ◽  
Geometric Constraints ◽  
Oscillating Water Column ◽  
Incident Wavelength ◽  
Significant Wave ◽  
Constructal Design

This paper aims a numerical investigation about the fluid dynamic behavior of an oscillating water column (OWC) wave energy converter (WEC) into electrical energy. Constructal design is employed to perform a geometric evaluation of an OWC WEC submitted a Pierson-Moskowitz wave spectrum. The objective function is to maximize the energy conversion. The hydropneumatic chamber volume (VHC) and the total OWC volume (VT) are adopted as geometric constraints. In the first stage, the values are constant during the maximization process. However, in a second stage they are changed according to the constraint variation (CV). One of the goals is to analyze the influence of the choice of this geometric constraints value on the OWC performance in relation to the wave spectrum. For this purpose, are considered three different scenarios: 1)VHydis equal to the minimum incident wavelength (λmin), that is relative to the maximum frequency of the wave spectrum times the significant wave height (HS); 2)VHydis equal to the peak incident wavelength (λpeak), that is relative to peak frequency of the wave spectrum times the significant wave height (HS); and 3)VHydis equal to the maximum incident wavelength (λmax), that is relative to minimum frequency of the wave spectrum times the significant wave height (HS). To do so, constructal design is employed varying the degree of freedom (DOF)H1/L(ratio between the height and length of OWC chamber), while the others DOF’sH2/l(ratio between height and length of chimney) andH3(lip submergence), are kept fixed. It is employed a Pierson-Moskowitz wave spectrum with significant period (TS) equal to 7.5 s and significant wave height (HS) equal to 1.5 m. For the numerical solution it is used the computational fluid dynamic (CFD) code, based on the finite volume method (FVM). The multiphase volume of fluid (VOF) model is applied to tackle with the water-air interaction. The computational domain is represented by the OWC WEC coupled with the wave tank. The results showed that whenCV= 2.25 forλmaxand (H1/L)O= 0.2152 the highest average for power was obtained, nearly 18,000 W. While forλminand (H1/L)O= 0.2193 it was smaller than 1,000 W. Besides, it was obtained a theoretical recommendation about the geometric constraints employed for the constructal design application, aiming the maximization of the OWC energy conversion from the incident wave spectrum.

scholarly journals AVALIAÇÃO GEOMÉTRICA DA CÂMARA DE UM DISPOSITIVO DE CONVERSÃO DE ENERGIA DAS ONDAS DO TIPO OWC PARA DIFERENTES COMPRIMENTOS DA BORDA FRONTAL

2017 ◽  
Vol 6 (3) ◽  
Author(s):  
Max Letzow ◽  
Felipe Vilela Levien ◽  
Rafael Dos Passos Pons ◽  
Mateus Das Neves Gomes ◽  
Jeferson Avila Souza ◽  
...  
Keyword(s):  
Water Column ◽  
Oscillating Water Column ◽  
Constructal Design

Este trabalho apresenta uma avaliação do desempenho de um dispositivo onshore de conversão de energia das ondas dos oceanos do tipo Coluna de Água Oscilante (Oscillating Water Column - OWC) em energia elétrica. O dispositivo é submetido à atuação de uma onda que é propagada ao longo de um canal com a presença do dispositivo OWC no final deste canal. As simulações numéricas consistiram na solução das equações de conservação de massa e quantidade de movimento para a mistura ar-água e uma equação de transporte para a fração volumétrica através do método de volumes finitos (MVF). A metodologia Constructal em associação com a busca exaustiva é aplicada a fim de determinarem-se as dimensões ótimas da razão entre a altura e comprimento da câmara hidropneumática do equipamento. Para tal, impõe-se uma restrição geométrica que fixa o valor da área da câmara em um valor constante. O objetivo do trabalho é avaliar a geometria que maximiza a potência do dispositivo para uma condição específica de onda, avaliar a influência do efeito entre altura e comprimento do dispositivo (H1/L1) sobre a potência disponível para dois diferentes valores de comprimento de borda frontal H3= 2,5 m e 5,0 m e verificar a existência ou não de uma geometria ótima universal. Verificou-se que a geometria ótima, a qual forneceu maior valor de potência hidropneumática, foi a geometria para o qual a razão H1/L1 = 0,4 e o comprimento H3 = 2,5 m. A condição de geometria ótima foi obtida para uma razão intermediária de H1/L1.Palavras-chave: Coluna de Água Oscilante, Avaliação Geométrica, Constructal Design.

The choice of geometric constraints value applied in the constructal design for Oscillating Water Column device

2017 ◽  
Author(s):  
Mateus das Neves Gomes ◽  
Matheus José de Deus ◽  
Elizaldo dos Santos Domingues ◽  
Liércio André Isoldi ◽  
Luiz Alberto Oliveira Rocha
Keyword(s):  
Water Column ◽  
Geometric Constraints ◽  
Oscillating Water Column ◽  
Constructal Design

scholarly journals TWO-DIMENSIONAL GEOMETRIC OPTIMIZATION OF AN OSCILLATING WATER COLUMN CONVERTER IN LABORATORY SCALE

2012 ◽  
Vol 11 (1-2) ◽  
pp. 30
Author(s):  
M. N. Gomes ◽  
C. D. Nascimento ◽  
B. L. Bonafini ◽  
E. D. Santos ◽  
L. A. Isoldi ◽  
...  
Keyword(s):  
Water Column ◽  
Geometric Optimization ◽  
Degree Of Freedom ◽  
Laboratory Scale ◽  
Computational Domain ◽  
Two Dimensional ◽  
Regular Wave ◽  
Oscillating Water Column ◽  
Worst Case ◽  
Constructal Design

The present paper presents a two-dimensional numerical study about the geometric optimization of an ocean Wave Energy Converter (WEC) into electrical energy that has as operational principal the Oscillating Water Column (OWC). To do so, the Constructal Design fundamentals were employed to vary the degree of freedom H1/L (ratio between height and length of the OWC chamber), while the other degree of freedom H2/l (ration between height and length of chimney) was kept constant. The OWC chamber area (φ1) and the total OWC area (φ2) are also kept fixed, being the problem constraints. In this study was adopted a regular wave with laboratory scale dimensions. The main goal was to optimize the device’s geometry aiming to maximize the absorbed power when it is subjected to a defined wave climate. For the numerical solution it was used the Computational Fluid Dynamic (CFD) commercial code FLUENT®, which is based on the Finite Volume Method (FVM). The multiphasic Volume of Fluid (VOF) model was applied to treat the water-air interaction. The computational domain was represented by an OWC device coupled into a wave tank. Thereby, it was possible to analyze the WEC subjected to regular wave incidence. An optimal geometry was obtained for (H1/L)o=0.84, being this one approximately ten times more efficient then the worst case (H1/L = 0.14), showing the applicability of Constructal Design in this kind of engineering problem.

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