VFG Support Structure
The movement of the water during the daily tidal cycle of our oceans requires tremendous amounts of energy that can be extracted mechanically as a perfectly clean and renewable source. This can be done with many machines such as the hydrokinetic turbine. The hydrokinetic turbine works the same as a wind turbine except, with water being a thousand times as dense as air, it has the potential to harvest significantly larger amounts of energy. We will be testing a hydrokinetic turbine design that features variable flux generation (VFG), which is designed to increase the efficiency of the turbine by reducing the required startup torque to spin the turbine.
The Turbine Deployment Structure is part of a joint venture to build and test the second generation Hydrokinetic Turbine featuring Variable Flux Generation (VFG). The motive behind building this test structure was to provide the turbine production team a platform to definitively test the VFG Turbine concept in a real-world ocean environment. Unlike past test structures, ours was designed to sustain larger horizontal axis turbines than can be tested in tow tanks. It was also designed to allow a great deal of simplicity and interchangeability for use in future projects. The success of our project depended on building a platform that had indisputable structural integrity, minimal drag and weight, allowing us to test the turbine without limitations on UNH’s 30 ft. test barge. Additionally, experimental measurements of the turbine’s efficiency, such as torque, rpm and power generation, had to be creatively implemented into the underwater design. The major goal of our project was to successfully design and build a structure capable of testing our sister group’s underwater VFG Turbine.
To achieve this goal, a number of intermediate goals were determined: design and build the support structure that will hold the turbine underwater, design and build the top frame which will attach the tripod to the barge, design and build a winch system capable of hoisting the tripod/turbine into place, mount top frame to the barge, perform Tank Test of tripod assembly both with and without a mock turbine weight applied to ensure structure sits true in water, and perform Hip-Tow test of barge both with/without tripod attached to determine approximate drag of support structure.
Available from the National Sea Grant Library (use NHU number to search) or NH Sea Grant
- VFG support structure (2011). Shane Baia and Chris Carrier. Advisors: Kenneth Baldwin and Martin Wosnik.