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The Computational Fluid Dynamics (CFD) Laboratory
Research On the Cutting Edge Cavitation in
Tidal Turbines
Prof. Steven Frankel and his lab team are working to
improve the performance of tidal power-driven turbine
blades that produce renewable energy in the deep seas
What: The Computational Fluid Dynamics (CFD) How: Tidal turbines present a
Laboratory focuses on the development and new form of renewable energy
implementation of high-precision numerical technology. Tidal energy, also
and physical models and on building turbulent- called “lunar energy,” converts the
flow simulations for application in numerous moon’s gravitational pull on the
areas, including aerodynamics, aeroacoustics, oceans’ waters into electricity. Tidal
cardiovascular, combustion, and multiphase turbines’ operation is similar to that
flows. CFD approaches are used primarily to solve of wind turbines, but they are placed
equations governing the behavior of fluids (such as underwater, harnessing a reliable,
air, water, etc.) using a numerical computer-assisted yet underused, source of energy.
method. Turbulence is an irregular state of fluid The technology is still in its infancy;
motion characterized by chaotic changes in pressure one of its challenges, encountered
and flow velocity. One of its familiar manifestations by the hydrokinetic industry during
is during flights, when passengers are asked to its application, is cavitation—a
fasten their seatbelts due to unexpected turbulence. phenomenon in which the evaporation
The computational simulation of turbulent flows process, designed to turn water into
presents a unique set of challenges, because of the gas under decompression, leads to the
wide range of lengths and time scales associated formation of small vapor-filled cavities
with turbulence; these require very precise inside the turbine. The cavities cause
numerical methods, mathematical models, and corrosion, due to their collapse once
high-performance computing. The CFD Lab currently the local pressure increases, and have
addresses several multidimensional problems an adverse effect on turbine blade
requiring such numerical methods, models, and performance. The CFD Lab team is
simulations. testing passive and active methods of
The growing global need for renewable energy has strategic control to reduce cavitation
led to the development of underwater turbines that and improve blade structure, as part
are powered by the natural rise and fall of the tides. of a project supported by the EU’s
One of the lab’s major research projects examines Horizon 2020 program.
cavitation in these turbines.
18 | MEgazine | Faculty of Mechanical Engineering