Page 60 - World Airnews Magazine December 2020

NEWS DIGITAL

OWL FEATHERS POINT THE WAY

TO LESS AIRCRAFT NOISE

A recent research study
conducted by City, University of
London's Professor Christoph
Bruecker and his team has
revealed how micro-structured
finlets on owl feathers enable
silent flight and may show the
way forward in reducing aircraft
noise in future.
Professor Bruecker is
City's Royal Academy of
Engineering Research Chair in
Nature-Inspired Sensing and After being transferred into a digital shape model, the flow
Flow Control for Sustainable Transport and Sir Richard Olver BAE simulations around those structures (using computational fluid
Systems Chair for Aeronautical Engineering. dynamics) clearly indicated the aerodynamic function of these
His team have published their discoveries in the Institute of extensions as finlets, which turn the flow direction in a coherent
Physics journal, Bioinspiration and Biomimetics in a paper titled way.
'Flow turning effect and laminar control by the 3-D curvature of This effect is known to stabilize the flow over a swept wing
leading edge serrations from owl wing.' aerofoil, typical for owls while flapping their wings and gliding.
Their research outlines their translation of the detailed 3-D Using flow studies in a water tunnel, Professor Bruecker, also
geometry data of typical owl feather examples provided by proved the flow-turning hypothesis in experiments with an
Professor Hermann Wagner at RWTH Aachen University (Germany) enlarged finlet model.
into a biomimetic aerofoil to study the aerodynamic effect on the His team was surprised that instead of producing vortices, the
special filaments at the leading edge of the feathers. finlets act as thin guide vanes due to their special 3-D curvature.
The results show that these structures work as arrays of finlets The regular array of such finlets over the wing span therefore turns
which coherently turn theflow direction near the aerodynamic wall the flow direction near the wall in a smooth and coherent manner.
and keep the flow for longer and with greater stability, avoiding The team plans to use a technical realization of such a swept
turbulence. wing aerofoil pattern in an anechoic wind-tunnel for further
The City research team was inspired by the complex 3-D acoustic tests. The outcome of this research will prove to be
geometry of the extensions along the front of the owl's feath- important for future laminar wing design and has the potential to
ers—reconstructed by Professor Wagner and his team in previous reduce aircraft noise. Q
studies using high-resolution micro-CT scans. Article courtesy: https://www.sciencedaily.com/

NEWS DIGITAL

NEXT AGM IN BOSTON

has taken place in the United States and forward to welcoming the leaders of the
the first time it comes to Boston. world aviation community to Boston, one
“Boston is an exciting choice for the of our key focus cities,” said Robin Hayes,
The International Air Transport 77th IATA AGM. With its rich history, chief executive officer of JetBlue Airways
Association has announced that JetBlue attractive setting and prestigious uni- and incoming chairman of the IATA board
Airways will host the 77th IATA annual versities, it is a popular global tourism of governors.
general meeting and World Air Transport destination. As the world reopens, Boston The decision to host the 77th IATA AGM
Summit in Boston, Massachusetts, on will be a bellwether city to observe the in Boston was made at the conclusion of
27-29 June 2021. shape of the recovery,” said Alexandre de the 76th AGM, which was held virtually
This will be the sixth time the pre-emi- Juniac, IATA director general and CEO. with KLM Royal Dutch Airlines as the host
nent global gathering of aviation’s leaders “JetBlue and our crewmembers look airline. Q

World Airnews | December Extra 2020
— 13 —