Tidal Power Plant: Capturing Tidal Power Using an Oscillating Wing

摘要

This report describes the iterative process and steps taken to build a tidal power generator which works efficiently while causing no harm to marine life or habitat. A tidal power generator is a device that converts the mechanical energy from the horizontal tides in the ocean (or any flowing water body) into electrical energy. The design was undertaken as an interdisciplinary capstone project for seniors in mechanical and electrical engineering. The results will be used for research purposes in determining the efficiency of the specific design used and the overall feasibility of tidal power generation. A preliminary prototype consisting of the mechanical linkages and an airfoil was built and tested in the air to prove the various concepts employed work. Based on the results obtained, a full scale model was built and tested in the wind tunnel. An elliptical airfoil was used in harnessing the mechanical energy from the tidal flow. A deflector mounted on the system was to make the elliptical airfoil work bi-directionally. The mechanical linkage consisted of a belt and four sprockets which enable the generator to only see rotary motion in one direction. Finally, a small electric motor was used as a generator to convert the mechanical energy harnessed into electrical energy. The tests performed show that tidal power generation through airfoils is a viable technology with a lot of potential. Using a bi-symmetric airfoil, 5mW of power was produced with a small six volt motor in 40miles/hour wind, with the airfoil moving at over 200 rpm. Rudimentary testing of the same system with an 85% efficient permanent magnet DC generator shows possibilities of over 50W. Given more time in the wind tunnel and the water tunnel (which were fully occupied by graduate students and broken respectively), more elaborate tests could have been performed on the tidal generator. Some improvements which can be made to the system include using lighter bellows seals that can collapse under their own weight, this would decrease the force required to move the airfoil and hence increase the rpm and power generation. Also, an improved design should include a control system that takes into account the flow speed of the water and consequently adjusts the angle of attack of the airfoil. The switching mechanism for the airfoil should also be improved to allow for bi-directional functionality of the system. The system met the majority of its functional requirements and with some minor improvements and more testing has the potential to be very successful.