NAOE Midshipmen Independent Research, EN495, EN496 and EN497
Midshipmen interested in pursuing research related to their degree have the opportunity senior year. The range of topics vary based on the requirements and funding of outside sources, as well as the research interests of faculty and midshipmen. The following midshipmen conducted research as part of Independent Research courses, EN495, EN496, and EN497 with Associate Professor Carolyn Judge, Professor Greg White, Professor Sarah Mouring, and CDR Andrew Gish.
Midshipmen First-Class Dave Silver worked on a multi-disciplinary independent research project with Midshipman First-Class Zac Dannelly to analyze the feasibility of constructing an offshore Data Center powered by ocean wave energy conversion devices. Advised by Professor Jeffrey Kosseff within the academic major Cyber Operations, Midshipman Dannelly researched the legal and technological components of building a Data Center offshore. Advised by Professor Sarah Mouring within the academic major Ocean Engineering, Midshipman Silver investigated the power output capability of oscillating water columns (OWCs). Considering the rules and regulations regarding data storage as well as the consistent large waves off its shore, an offshore Data Center is proposed 30 miles off the west coast of Ireland. While experimental and theoretical data on a single OWC exists, minimal experimental data on an array of OWCs is available. Mr. Bill Beaver constructed and tested an OWC for initial data.
With the assistance of Midshipman Second-Class Pat Robert, Midshipman Silver submitted designs for four identical OWCs and tested various arrays of the OWCs in USNA Hydro Lab's 120 foot towing tank. Midshipman Silver presented the research at IEEE/MTS OCEANS Conference in Shanghai in April 2016, where he was selected as one of 16 and the only American in the Student Poster Competition, from an applicant pool of 125 international students.
Pictures: OWCs in the 120 foot wave tank for testing
Pictures: Conference presentation
Midshipman First-Class David Tauber is investigating vertical accelerations on a planing hull with varying levels of freedom of surge. Planing hulls are high-speed vessels that experience less resistance than a normal displacement ship, but the safety of passengers is hindered by vertical accelerations as the hull slams across waves. The research consists of modifying towing tank tests on planing hull models to allow freedom to surge effects. Historically, lab tow tests use a rigid tow post to support the ship model, but does this really model the motions of a planing hull in waves correctly? In 1971, Professor Gerard Fridsma of Stevens Institute of Technology completed a series of towing tank tests and wrote that freedom in surge does not change the vertical accelerations passengers experience while riding in a planing hull. Test one will be a baseline, using a planing hull connected to a rigid towing post (normal towing tank test) with degrees of freedom in pitch and heave. Test two will use a freed to surge rig that includes a spring and dashpot to more accurately model freedom in surge. Test three will use a motor, propeller, and a rudder to again more accurately model the effects of freedom in surge. The intent is not to challenge Professor Fridsma’s claims, but rather to use more modern and advanced techniques to see if his claim was right about freedom in surge effecting vertical accelerations and passenger safety. The research is advised by Associate Professor Carolyn Judge, Professor Greg White, Mr. Bill Beaver, and Mr. John Zseleczky.
Pictures: Planing model hulls in towing tests
Midshipman First-Class Angela Carandang continued the research from two semesters with improving efficiency in hydrokinetic turbines. The previous two semester improved hydrokinetic turbines through the use of a shroud to direct the flow towards the turbine. The current project aims to improve turbine performance through the use of pre-swirl stator blades. Pre-swirl stators alter the turbine inlet flow so as to maximize the blade lift in the rotational direction. The stator parameters to be chosen were the foil shape and the angle of attack. The foil shape was selected by evaluating several standard foil shapes and selecting the ones with the highest stall angle and highest lift/drag ratio. Flow simulations were run with the selected foils at angles of attack based on velocity behind the stator blades and the optimal streamline flow around the blade. The optimal condition was the one which produced a flow angle in the desired range with the highest velocity magnitude. Following determination of the optimal foil shape and angle of attack, a 3D model of the shroud with stators was created in SolidWorks and analyzed for future physical testing.
Pictures: 3D computer model of water flow over stator blades and shroud
Underwater turbines are a method to harness renewable energy from streams or rivers. Midshipman First-Class Gavin Hawbaker attempted to optimize the efficiency of a horizontal hydro-kinetic turbine through use of a shroud. The shroud wraps around the turbine propeller, designed to increase the velocity of water through the turbine, thus producing more renewable power output. The shroud works because of a pressure differential between the front and back of the shroud. With the assistance of his adviser, CDR Andy Gish, Midshipman Hawbaker completed initial tests that prove the success of the shroud by increasing turbine efficiency by 18 percent.
Click each turbine to download a VIDEO in action.
Midshipmen First-Class Brendan Klovekorn and Alec Morgan constructed a Augmented Reality Sandbox that allows a 3D contour map to be projected on top of a specified area of sand. As the sand is moved around to create mountains and valleys, the projector updates the map in real-time, actively displaying changes in elevation. This concept allows for a number of experimental scenarios to be run in a given area. The ability to see and track changes in real-time is especially important for measuring shifts in the coastal environment. As opposed to using remote sensing over a long period of time to track changes in the littoral zone, the Augmented Reality Sandbox can simulate adverse weather and oceanographic conditions in a much shorter time frame, providing meaningful results that can be used in prevention rather than repair. The Microsoft Kinect system is very sensitive to small shifts in the sand, allowing for even slow and gradual processes such as erosion to be observed and altered. In extreme storms, changes can happen very rapidly, and the speed at which the Kinect measures changes (~30 frames per second) will be a significant asset in this regard as well.
Pictures: Augmented Reality Sandbox system