8th July 2019
Progress meeting. Focus on Wave Dragon only for this week. To do:
- draw detailed design of Wave Dragon
- design the reservoir: how to accumulate water to a certain level before directing them to the turbines
- read on Kaplan turbine: how much water needed to operate the turbine
9th July 2019
Read on the structure of the Wave Dragon. They are constructed with open air-chambers where a pressurised are system makes the floating height adjustable. Thus, the crest freeboard can be adujsted to yield the maximum overtopping efficiency in different wave conditions. Open air-chambers reduce the movements of the main body, as the wave induced pressure on the underside of the the structure compresses air rather than moving the body.
10th July 2019
Read on the prototype design which was deployed in Nissum Bredning. It was constructed using steel plates which weights about 150 tonnes. The total weight including the ballast was 237 tonnes.
Also read on the PTO. Once the overtopping water has reached the reservoir, the potential energy is harvested by the installed low-head turbines. The operating conditions of the turbines on the Wave Dragon differ strongly from those in a normal river hydro power station. Firstly, the turbines have to operate at very low head values ranging from 0.4m to 4.0m, which is not only on the lower limit of the existing hydro power experience, but also an extremely wide variation. Secondly, due to the stochastic time distribution of the wave overtopping and the limited storage capacity, the turbines have to be regulated from zero to full load very frequently. Lastly, they have to operate in a very hostile environment with only a minimum of maintenance being possible on an unmanned offshore platform.
11th July 2019
Search for suitable turbines which can be used in the Wave Dragon that are available in the market. Did rough sketch of some design ideas based on readings and findings. Found that it is quite difficult to identify the appropriate location to place the turbines as they require low head to operate.
12th July 2019
Progress meeting. After explaining the design ideas to Dr. Khairi and further discussion on the low head turbine problem, Dr, Khairi proposed a simpler concept which uses electromagnetic induction. Also today was a briefing by Dr. Irza on another project: Anthropometric Data of ASEAN Adults & Children for ASEAN NCAP. We will involved in this project from time to time.