Analysis of FSI effects for a novel WEC using high-fidelity simulations
Ladda ner
Typ
Examensarbete för masterexamen
Program
Applied mechanics (MPAME), MSc
Publicerad
2022
Författare
John Jawahar Edwin, Jason Ebenezer
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Wave energy is more reliable and continuous in time, compared to solar and wind
energy which are more periodic. The World Energy Council predicts that wave
energy has the potential to meet 10-20% of the world’s energy demands. A wave
energy converter (WEC) as the name suggests, harvests energy from the vertical
motion of waves. The WEC is anchored in an offshore location, using mooring lines
attached to the sea floor. The generated electricity is transmitted to a grid on-land,
since the WEC does not have an energy storage system, to keep the weight of the
WEC low. In this project, a WEC is studied using the commercial CFD code STARCCM+.
The WEC is designed by Novige AB called NoviOcean 500. The primary
objective is to study the forces acting on the surface of the buoy as a result of the
heave, surge and pitch motions, which affect the power generation and the stability
of the buoy in the waves. It is equally important to study the mooring line forces
of the WEC, for design estimations of the mooring line material and size. A mesh
independence study is done to ensure the results of the study are mesh independent.
The different wave generation models, the fifth order Stokes wave and irregular wave
models are considered, with the irregular wave model being found more suited for
short sea states, like stormy sea conditions. And the fifth order Stokes wave more
uniform and regular in nature. Various wave parameters which affect the heave
motion of the WEC, like wavelength and wave period are studied. A nominal wave
period between 5-9 seconds is used to depict normal sea wave conditions. Finally,
the linear spring and catenary coupling models are used to study the differences in
heave motion, coupling elongation and coupling forces. From the thesis work, it is
concluded that the use of the fifth order Stokes wave model, with a wave period of
between 5-9 seconds and a catenary coupling model for the mooring lines, is a good
simulation setup for the study of the NoviOcean 500.
Beskrivning
Ämne/nyckelord
WEC, buoy, CFD, wave energy, mooring, overset mesh, fluid structure interaction , buoy , CFD , wave energy , mooring , overset mesh , fluid structure interaction