MIT student Fiona Grant spent her summer internship in FSI working with Drs Nick Townsend and Gabe Weymouth working on the Maritime Robotics Lab vehicle Fleur. She uses wave energy to self propel herself into or with the waves.  Fiona’s report below details some of her activities.  We enjoyed her company and that of our five other interns and are grateful to our funding partners for their support and in particular the University’s EXCEL scheme.

This summer I worked on a project studying the behavior of flapping foil systems. Flapping foils are devices modeled on the swimming mechanism for cetaceans and many fish. These devices have been widely researched, and it has been shown through experiments and simulation that flapping foils can be used to both harvest energy and produce thrust. The relationship between the magnitude and phase of the foil heave and pitch motions defines these two modes. Flapping foils have been successfully implemented in several full scale applications, including ships and wave energy converters (WECs). Currently, the optimal control and stability of flapping foil systems is being investigated, and more research is needed to solve this problem.
The system for this project was a model vessel with a pair of flapping foils attached at the stern. The goal for the summer was to gain an understanding of the dynamic behavior of the system and design a velocity controller for the vessel. I began by modeling the dynamics of the vessel and a single foil in calm water. I then worked on setting up the hardware, LabVIEW code, and driver software to control the linear motor that actuates the foil. In the final two weeks, we were able to run tests in the towing tank and collect data on the open loop response of the vessel and foil system for a range of frequencies and amplitudes.
This internship was a great experience. I was able to put my knowledge of control theory and experimentation techniques into practice and affirmed my desire to study control systems in graduate school. Throughout the internship I was able to work with computer simulation, hardware and software integration, and model testing. During my project I had guidance from my supervisors, but also a level of independence that allowed me to explore the topic and make my own choices about the research. I now feel more prepared for graduate school and excited about continuing my studies.