PREDICTION OF DIFFRACTION FORCES ON A WAVE ENERGY CONVERTER USING BEM AND CFD APPROACH
1 online resource (55 pages) : PDF
University of North Carolina at Charlotte
Alternative energy sources address concerns about fossil fuels such as environmental degradation, public health, and ﬁnite energy source. Compared to wind and solar powers, wave power has a higher energy density and is easier to forecast. However, non-linear, complex, and turbulent nature of oceans necessitates a more in-depth ﬂow ﬁeld analysis before the deployment of wave energy converters (WECs). This research explores the performance of a two-point body absorber WEC, Reference Model 3 (RM3) introduced by the Department of Energy (DOE), to be deployed in North Carolina shores. The wave data from US 192 and US 430 buoy stations were used to calculate the hydrodynamic forces, with focus on the diﬀraction and Froude-Krylov forces in this work, on the RM3 using1. DOE WEC-Sim, a boundary element method-based (BEM) approach2. Computational ﬂuid dynamics (CFD), a ﬁnite volume method-based approachIn the ﬁrst approach, a full-scale model of RM3 was studied. In the second approach, using the wave characteristics and ocean depth along the North Carolina shores, three scalded RM3 models: 50th, 100th, and 200th, were studied. The developed CFD model based on the volume of ﬂuid (VoF) Eulerian multiphase ﬂow was initially validated with published computational and experimental literature. The realizable k− turbulence model was employed to study the eﬀects of ocean wave turbulence. The validated model was used to study the generated 5th order approximation Stokes wave on the RM3. The grid analysis, using cell sizes ranging from 2.8 million to 9.4 million, veriﬁed the appropriate mesh resolution of 7.2 million on the ﬂoating part of the RM3. The main challenges faced during the computational domain setup such as free-surfacemeshreﬁnement, boundary conditions,preventingwavereﬂection, and scaling the model are elaborated and appropriate solutions are stated. Next step of this research includes modeling the radiation forces to determine the total hydrodynamic forces on the RM3 when deployed as a stand-alone or an array along the North Carolina shores. Also, ongoing experimental testing within the NADGOD research group on scaled RM3 models will be validated and verify the developed CFD model.
Keanini, RussellUddin, Mesbah
Thesis (M.S.)--University of North Carolina at Charlotte, 2018.
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). For additional information, see http://rightsstatements.org/page/InC/1.0/.
Copyright is held by the author unless otherwise indicated.