Numerical study of fixed Oscillating Water Column with RANS-type two-phase CFD model

Highlights

Validation of open-source CFD model for OWCs against experimental results produced for this scope.

Tests include irregular and regular wave conditions for performance, OWC response and reflection coefficients.

Analytic design of the numerical wave tank is presented and ways to handle the computational cost.

The OWCs are tested without PTO highlighting potential uses as absorbing sea walls.

A decay analysis based on mechanical vibrations is used to estimate the resonance of the OWC.

Abstract

Various studies investigated the behaviour and the performance of Oscillating Water Columns (OWCs) suggesting many alternative design concepts to improve the efficiency of the device. The OWCs examined here are fixed on the seabed and have a slit opening at the seaward side. The present study investigates the applicability of a multiphase Reynolds Averaged Navier-Stokes (RANS) numerical model for simulating the interaction between an OWC and regular and irregular waves. An initial validation of the open-source computational fluid dynamics (CFD) software package OpenFOAM with the wave generation and absorption toolbox waves2Foam is performed against experimental results obtained at the COAST laboratory of the University of Plymouth. The main aim of the study is to complement to the validation of RANS CFD models and later employ the broadly used numerical tool for further studies for better understanding the behaviour of the OWCs. A method based on mechanical damped oscillations for calculating the eigen frequency of the device from a decay test is presented and compared with the performance curve. The strength of CFD modelling for obtaining better insight to the hydrodynamics of OWCs is also demonstrated.

Keywords

  • CFD;
  • OWC;
  • Validation;
  • OpenFOAM;
  • Waves2Foam;
  • Hydrodynamics

Be the first to comment

Leave a Reply

Your email address will not be published.


*