Invention: Turbines and fans inspired by whales
A team consisting of an American biologist, a US/Canadian aeronautical engineer and a Canadian inventor and entrepreneur looked to nature to develop quiet and efficient turbines, industrial fans and blowers. Their biomimetic turbine blade design is based on the "bumpy" flippers of humpback whales and can help wind farms produce up to 20% more power and increase airflow by up to 25% in industrial fans and blowers.
Turbine aerodynamic performance has been significantly
improved and noise reduced thanks to the tubercle technology developed by biologist
Frank Fish, aeronautical engineer Philip Watts and film-maker, inventor and
entrepreneur Stephen W. Dewar. This team achieved its breakthrough after Fish discovered
that tubercles - the small bumps on the leading edge
of humpback whales' flippers - reduce unwanted whirling masses of air called vortices,
thereby reducing drag while simultaneously increasing lift.
The discovery
challenged conventional aerodynamics wisdom, which had long held that the leading
edge of propellers, blades and turbines should be as smooth as possible to
limit air resistance. It turns out that these specially placed bumps can deliver
a significant increase in performance. To transform this insight into
blade designs for wind turbines, cooling fans and industrial blowers, the team set up the start-up WhalePower, which now licenses the technology
to prospective manufacturers.
Societal benefit
Able to boost the energy production of wind farms by up to 20%, while producing less noise
and requiring less maintenance, the technology holds tremendous
potential for the wind power sector.
WhalePower's tubercle
technology concept was licensed to a German green energy producer which commissioned
the German Aerospace Center to study model wind turbine blades equipped with
tubercles in a wind tunnel. They found that noise was reduced by at least 2 decibels
and material wear by 6 to 8%, and the lifetime of key components
extended by 25% - the equivalent of three to six more years of use given the
average 12 to 25-year lifetime of a wind turbine.
For fan and turbine applications that use, rather than
produce, energy, tubercle blades can increase air circulation by up to a
quarter while requiring less energy. A leading manufacturer tested a prototype
fan for cooling computer graphics cards and found the design to be about 20%
more efficient than the current market leader. This is a compelling proposition
to the IT industry where fans and cooling consume around 10% of the total power
in certain applications, such as servers.
Economic benefit
WhalePower operates as a virtual intellectual property firm,
licensing its designs to other companies that wish to use the technology in their particular areas of
expertise.
The company introduced the first tubercle-blade high-volume,
low-speed (HVLS) fan to the market through its licensee Envira-North Systems.
Called the Altra-Air, this industrial-scale fan is available in a range of sizes
in 38 countries. It promises 20 000 hours of maintenance-free
operation while consuming as little energy as an average hairdrier, and circulates
about 25% more air than similar, non-tubercle fans. A second HVLS fan
manufacturer, Shanghai Fast Link, also sells HVLS fans with tubercles in China.
Global sales in the wind turbine market are expected to grow
from EUR 64.5 billion in 2015 to EUR 66 billion in 2019.
The global market for industrial and commercial fans and blowers, where
WhalePower has its first licensed product, is forecast to be worth some EUR 8.5 billion
by 2022.
How it works
Fish, a leading expert on the biomechanics of how animals
swim, surmised that the saw blade-like edge on humpback whales' fins could be a
reason for the large mammals' remarkable endurance and speed (they weigh some
30 metric tonnes). Fish's early studies of the flippers suggested that the
tubercle bumps improved lift.
Fish
wrote a research paper confirming his findings that captured Watts' attention.
The two teamed up to investigate the phenomenon more closely and to see if it
might have practical applications. A typical aerofoil, they found, actually has
to fight against the turbulent airflow it creates at its own tip. This results
in vortices (whirling masses of air) that reduce efficiency and create extra
noise.
Joined
by Dewar, the team set up WhalePower to develop, patent and
market their new blade design. By incorporating tubercle-inspired bumps, which they
rounded and streamlined for maximum aerodynamic and fluid dynamic effects, they
were able to increase the maximum lift of a wing while softening stall over
what is termed the angle of attack by up to 40%. The net result was an
efficiency gain of roughly 20% when using a blade with a tubercle-fitted front
edge on a wind turbine. The more efficient leading-edge design could operate at
a greater pitch (the angle to oncoming wind) and still continue to produce
power in less windy conditions.
The inventors
After earning his PhD from the Zoology Department of
Michigan State University in 1980, Frank Fish became a Professor of Biology at West Chester University of Pennsylvania, a
position he has held ever since. He runs the Liquid Life Laboratory there and his
research is focused on the energetics and hydrodynamics of vertebrate aquatic
locomotion and biomimetic applications. His work on the biomechanics of aquatic
mammal propulsion has been funded by the US Defense Advanced Research Projects
Agency, National Science Foundation and Office of Naval Research. Fish has
worked as a university professor, research scientist and inventor for more than
40 years. He has published around 150 research articles, government
reports and book chapters.
Since earning his PhD in Environmental Engineering Sciences
from the California Institute of Technology in 1997, Philip Watts has developed
and patented advances in the field of wind turbine technology and served as an
executive at several wind power companies. He is currently CEO of ReSource
Renewable Energy. He served as Vice President of R&D at WhalePower, where
he designed a high-lift-to-drag-ratio wind turbine blade. Watts has also
published scientific papers on the aerodynamics of bat flight as well as astronaut
movement on space stations. He has authored over 70 scientific
publications and reports during more than 14 years of research.
A prolific inventor and entrepreneur, Stephen W. Dewar's
interests include scientific publications and science journalism. He first heard
about Fish and Watts' successful research on Canadian Broadcasting Corporation
(CBC) radio's Quirks and Quarks and
decided to reach out; he ultimately became a partner in their company. He has
spent the last 30 years writing, directing and producing hundreds of radio
and television documentaries as well as dramas and comedies for the CBC, the
National Film Board of Canada, CTV and CBS.
Did you know?
Many inventors have looked to nature for inspiration
or to improve their inventions. Billions of years of evolution are a powerful test
bed for a whole host of designs.
Past winners of the European Inventor Award whose
inventions took their inspiration from nature include Peter Holme
Jensen, Claus Hélix-Nielsen and Danielle Keller (2014; SMEs) for
their energy-efficient water purification based on aquaporins and Adnane Remmal (2017; Popular
Prize) for his antibiotics boosted with essential oils. Award finalists with
inventions based on biomimicry include Fiona Fairhurst for her swimsuit based
on shark skin (2009; Industry) and Miroslav Sedláček for his rolling
fluid turbine (2016; Research).
