Numerical Analysis including Pressure Drop in Oscillating Water Column Device

Abstract The 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.

[1]  Cláudio Rodrigues Olinto,et al.  Computational Modeling of a Regular Wave Tank , 2009 .

[2]  Qingping Zou,et al.  Numerical simulation of overflow at vertical weirs using a hybrid level set/VOF method , 2011 .

[3]  Michael Horko,et al.  CFD optimisation of an oscillating water column wave energy converter , 2007 .

[4]  J. W. Weber,et al.  An Investigation Into the Importance of the Air Chamber Design of an Oscillating Water Column Wave Energy Device , 2001 .

[5]  J. M. Paixão Conde,et al.  Numerical study of the air-flow in an oscillating water column wave energy converter , 2008 .

[6]  Chia-Jung Hsu Numerical Heat Transfer and Fluid Flow , 1981 .

[7]  R. Fujita,et al.  Renewable energy from the ocean , 2002 .

[8]  António F.O. Falcão,et al.  Wave energy utilization: A review of the technologies , 2010 .

[9]  J. A. Souza,et al.  Numerical Study of the Effect of the Relative Depth on the Overtopping Wave Energy Converters According to Constructal Design , 2014 .

[10]  C. R. Olinto,et al.  Computational Modeling of a Regular Wave Tank , 2009, 2009 3rd Southern Conference on Computational Modeling.

[11]  A. Miguel,et al.  Ocean exergy and energy conversion systems , 2012 .

[12]  Weeratunge Malalasekera,et al.  An introduction to computational fluid dynamics - the finite volume method , 2007 .

[13]  Beom-Soo Hyun,et al.  Numerical study of air chamber for oscillating water column wave energy convertor , 2011 .

[14]  J. A. Souza,et al.  Constructal Design of Wave Energy Converters , 2013 .

[15]  L. Rocha,et al.  Two-dimensional geometric optimization of an oscillating water column converter of real scale , 2013 .

[16]  Alan S. Fung,et al.  Review of marine renewable energies: Case study of Iran , 2011 .

[17]  Beom-Soo Hyun,et al.  Investigation On Integrated System of Chamber And Turbine For OWC Wave Energy Convertor , 2009 .

[18]  C. W. Hirt,et al.  Volume of fluid (VOF) method for the dynamics of free boundaries , 1981 .