Design And Study On Wave Energy Devices Integrated Into Comb-type Breakwater

The integration of the plant structure into a breakwater has a cost advantage, andthe access for construction, operation and maintenance of the wave energy plantbecome much easier.Based on the physical model test on stability of a comb-type breakwater, designand study on wave energy devices has been carried out.Considering the working conditions and constrains of comb-type breakwater,wave direct drive (WDD) energy converter and oscillating water column (OWC)energy converter are considered to be the right converters.In the present thesis, a two–dimensional numerical wave flume is built based onCFD numerical model Flow-3D. Effort has been made to validate the propagation ofthe wave and the wave profile. Several numerical model tests were carried out to testthe WDD device in that numerical wave flume under regular wave conditions, resultsare discussed. A most efficient profile of breakwater was found, but the efficiency isrelatively low.A physical model of the most efficient profile was built to validate the numericalsimulation results and to test its energy convert capacity. The difference between a2-D numerical wave flume and a3-D wave flume makes the physical model testresults disagree with the numerical results to some extent. But the efficiencies arealmost the same. Test results of the same model with different wave periods showsthat the distance of water particle travels in a half wave period dominant the totalefficiency. The interaction between wave crest and upper inclined boundary plays animport role in the energy transmission.A2-D numerical OWC model was built to investigate its hydrodynamicperformance. Natural frequency of the oscillating water column was studied by asimple numerical model. A lip submergence was provided. The numerical wave flumewas modified to simulate this two fluid situation. Results illustrated that with the samevent ratio, a smaller width of the OWC body lead to a better energy convertperformance.