MHL: Marine Hydrodynamics Laboratory

The MRELab is dedicated to developing technology to harness the abundant, clean, and renewable marine energy in an environmentally sustainable way and at a competitive cost. The current focus of the MRELab is to study the underlying science of the VIVACE Converter, which was invented in the MRELab (three patents pending) to harness the hydrokinetic energy of ocean/river currents/tides.

Marine Renewable Energy: Water is the largest and natural medium for energy storage. If we could harness just 0.1% of the ocean energy we would be able to cover the energy needs of 15 billion people. Of the solar energy available to Earth, 285 ZJoule/year are absorbed in water, 6 ZJoule/year are theoretically available in wind, and 1.8 ZJoule/year are absorbed in biomass. Worldwide energy consumption was 0.471 ZJ in 2004. Marine renewable energy comes in five forms: currents, waves, tides, thermal gradient, and salinity gradient.

Sustainable Energy Harnessing: The primary challenge the World faces today is generation of renewable energy in an environmentally sustainable way at a competitive cost. Dams create major environmental problems. Turbines require an average of 5-7knots to be financially viable, while the vast majority of currents flow at speeds of less than 3knots. Concerns have also been raised regarding impact of turbines on marine life. VIVACE is based on VIV, a natural instability phenomenon, which is further enhanced using passive turbulence control and fish biomimetics.

The VIVACE Converter: VIVACE (Vortex Induced Vibration for Aquatic Clean Energy) is designed to: enhance rather than spoil vortex shedding; maximize rather than suppress VIV; harness rather than mitigate VIV energy. In 2005, the concept was model-tested in the Low Turbulence Free Surface Water Channel (LTFSWChannel) of the Marine Hydrodynamics Lab (Video at www.vortexhydroenergy.com). VIVACE takes the naturally catastrophic phenomenon of VIV and successfully transforms it into a means of tapping into a virtually untapped energy source: the hydrokinetic energy of currents with speeds even less than 2knots. VIVACE is equally effective at high speeds as VIV is highly scalable. VIVACE is environmentally compatible technology estimated to generate energy at $0.055/kWh at maturity.

Facilities: Model testing is performed in the LTFSWChannel. A prototype is being designed for large lab and offshore testing in the Detroit River. Simulations are based on CFD, energy phenomenology, and calibration. Model parameters include: Reynolds Number Re [8x103 -1.5x105], mass ratio m* [1.0 -3.14], ] current velocity U [0.35 m/s -1.15 m/s, aspect ratio L/D [6 - 36], mass-damping m*? [0.14 -0.26], and spring stiffness. Four design parameters for Passive Turbulence Control via surface roughness and three fish-tail parameters complete the current matrix of parametric tests.

Education: Since the inception of MRELab in the summer of 2005, 29 students have worked or are working in the lab at all degree levels: 8 PhD's; 1 PE; 2 MBA's; 5 MEng's; 2 MSE's; and 11 undergrads. Students study marine hydrodynamics, designing and conducting experiments, boundary layers, vortex induced vibration, laser visualization, energy harnessing, power take off, system integration, passive turbulence control, fish-biomimetics, marine renewable energy, environmental impact of energy harnessing, tech-transfer off an innovative idea, patenting process.

Research: PhD and publication activities focus on the following topics: (1) Enhancement of high damping VIV for energy harnessing, (2) expansion of the TrSL3 regime of high lift, (3) optimal VIV damping for energy harnessing, (4) electromagnetic power take off, (5) high damping VIV hysteresis, (6) passive turbulence control for VIV enhancement. (7) fish biomimetics for energy harnessing, (8) CFD and calibration of cylinder flows in VIV, (9) flow past cylinder arrays, (10) energy phenomenological modeling, (11) VIV under nonlinear spring restoring force.

MRELab Team: Director: Prof. Michael M. Bernitsas, Ph.D.; Research Scientist: Kevin Maki, PhD.; PhD students: Elisha MH Garcia, Jim Chang, Jonghun Lee, Wei Wu, Deborah Osborn, Hong Rae Park, Eun Soo Kim; UG NA&ME design group: Erin Bachynski, Grzegorz Filip, Kaz Sasahara, Matthew Redmon; UG ME power take-off group: Jeffrey Bondalapati, Kevin Crimmins, Quang Nguyen, Kevin Wolf, Zhili Zuo.