Ohmsett, the National Oil Spill Response Research and Renewable Energy Facility, hosted last week a Bureau of Safety and Environmental Enforcement (BSEE)-contracted team of scientists from the New Jersey Institute of Technology (NJIT) who evaluated the ability of the test tank wave generator to produce breaking waves at designated areas in the tank.
BSEE maintains and operates the Ohmsett facility, which is used by numerous government agencies, private companies, academic organizations and international organizations to conduct oil spill response research, testing and training. According to BSEE, the Ohmsett facility houses the largest wave/tow tank in North America; marine energy-related technologies are also tested there.
BSEE is working to develop a means of generating predictable and reproducible breaking waves in the tank to be able to quantify and compare the effect of the energy from breaking waves on oil mitigation systems and energy-capturing devices. The NJIT team experimented with two methods for generating breaking waves at pre-set locations and time intervals, while collecting wave data to be analyzed with a fluid dynamics software program.
The team also assessed wave reflections from the tank’s artificial beach system for possible improvements, the bureau said. The tank is equipped with a wave generator that can be programmed to produce varying types of waves. At the opposite end is a “beach” system that reduces reflection from the incoming waves.
However, previous tests have shown that a considerable amount of reflection still occurs in the tank, BSEE noted. The team will use the data obtained from this research to design a physical grid-like barrier that could replace the present beach system to create drag and turbulence in the water, dissipating the incoming wave energy. The grids could be raised or lowered as needed, and would be designed for easy cleaning and maintenance. Decreased reflection in the tank could better emulate natural ocean waves and make future oil spill response and energy harvesting technology tests more accurate and reproducible.
Ohmsett is located at the Naval Weapons Station Earle Waterfront in Leonardo, New Jersey. Its 667-foot long above-ground concrete test tank allows testing of full-scale equipment in realistic sea environments, while data collection and video systems record test results.