Biomimicry of Owl Wings
Aerofoils such as aircraft wings, helicopter rotors and wind turbine blades, can create significant noise, which can be a nuisance. Researchers at Chiba University in Japan and Shanghai Jiao Tong University in China have been analysing the silent flight of owls to understand how the wing features reduce noise. Compare the loud flapping of a pigeon with the noiseless flight of an owl, and the optimisation of owl wins is apparent. The researchers concluded that owl wings are optimised for high lift with minimal flapping, and this is promoted by leading-edge serrations, trailing edge fringes and velvet-like surfaces. Hao Liu from Chiba University commented; "We wanted to understand how these features affect aerodynamic force production and noise reduction, and whether they could be applied elsewhere." They found that the wing features controlled the transition from laminar to turbulent flow on the upper wing surface when the angle of attack was altered.
Talking of noisy aircraft, we all knew that Concorde was way ahead of its time – providing passenger flights at supersonic speeds, and now two new projects have been in the news. This year, US company Boom Technology has raised additional funding of US$33m, totalling $41, to develop a new commercial supersonic aircraft, that can cruise at Mach 2.2 with a target ticket price for London-New York at $5000. The company has produced a one-third scale prototype called XB-1 for testing this year.
In parallel, engineers at Armstrong Flight Research Center, NASA, are working with Lockheed Martin on another supersonic passenger aircraft project, called, pointedly, the Low Boom Flight Demonstrator. The target is to reduce the level of sonic boom generated so that the aircraft can fly supersonic over land rather than supersonic limited to over-sea operations.
Still in the subject of flight, the Siemens electric aerobatic plane named Extra 330LE this year broke the record for the fastest e-plane under 1000kg. Powered by a Siemens electric motor capable of continuous output of 260kW climbed to an altitude of 3000 metres in 4 minutes 22 seconds (11.5 m/s), a new world record. In a 3km straight line flight, the aircraft recorded a speed of 209.7 mph (337.5 km/h) which was 13.48 km/h faster than the previous record set in 2013. The plane also towed a LS8-neo glider to 600 metres in 76 seconds. Siemens are collaborating with Airbus on a future hybrid-electric aircraft .
Another record was achieved by the Proterra Catalyst E2 electric bus, which completed a 1,101.2 mile journey using a new dual-motor drivetrain, the DuoPower. The Catalyst is claimed to be 5 times more efficient than a standard diesel bus and 20% more efficient than the standard powertrain. The two electric motors deliver 510 hp achieving 0-20 mph up 26 percent inclines in 4.5 seconds. This is twice the performance of a standard diesel bus, and has a nominal range of 426 miles (660 km). Source Proterra.
Electric Car Platform
Electric cars are now rarely out of the headlines. Williams Advanced Engineering announced in September that it has developed an electric vehicle chassis for safer, lighter, more efficient vehicles. The FW-EVX concept combines composite components such as CFRP suspension with a high strength 3D exoskeleton for the battery pack .
How would you fancy pedalling along at 70mph? The Gulas Pi1S is a 38hp e-bike with 100Nm of torque. The running gear is more motorbike than bicycle, and prices start at around £20k.
Toshiba Fast-Charge EV Battery
Toshiba has developed a fast-charge battery which they claim could triple the range of EVs, then allow charging in minutes. The SCiB (Super Charge ion Battery) can charge to 90 percent capacity in 5 minutes, and is used in Mitsubishi’s I MiEV and Honda’s Fit EV. The previous lithium titanium oxide anode has been replaced with an anode made from titanium niobium oxide in a crystal structure that stores Lithium ions more efficiently. A 50Ah version of the battery has been shown to retain 90 percent capacity after 500 charge cycles. It is estimated to give a compact EV a range of 186 miles after a 6 minute ultra-rapid charge.
Graphene Synthesis Route
Prof Doug Adamson at UConn Institute of Materials Science has patented a novel method for manufacturing pristine graphene from graphite. The graphite is placed at the interface between oil and water, and the graphene sheets spontaneously spread to cover the interface. The graphene sheets are overlapping, and can be locked in place using a cross-linked polymer. They have applied the material for to purification using a technique called capacitative deionisation or CDI.