Source : THE AGE NEWS
Much of aviation’s history hinges on what humans learn from birds about aerodynamics. But the next leap forward may be driven not by birds, but by sharks.
Particularly, the shark’s skin, which features microscopic grooves that reduce drag as the animal swims through water.
MicroTau staff install a sample of the company’s sharkskin drag reducing material on a section of an Airbus aircraft at the Sydenham site. Credit: Kate Geraghty
The concept is being applied to the surface of planes to reduce their drag and boost their efficiency, trimming fuel costs in the process.
Sydney-based MicroTau, the company pioneering this application of technology, is partnering with low-cost Spanish airline Vueling to support the certification of its “shark skin” Riblet Modification Package.
Vueling is supporting the certification by the European Union Aviation Safety Agency of MicroTau’s shark skin material, seen as the first step in mainstreaming a more aerodynamic surface for commercial jets.
Crucially for airlines, which spend billions to buy and maintain fleets, often with years of lead time, the riblet modification doesn’t require any structural changes to the plane.
Based on current savings applied to current commercial fuel burn, across the industry, could save about $US8 billion ($12 billion) a year.
Riblets are grooved surfaces aligned with the airflow. MicroTau’s products are applied to the wings and fuselage of planes. MicroTau co-founder Henry Bilinsky says that when 80 per cent of a plane is covered in the riblets, flying at cruise conditions, it could save 3 to 4 per cent in fuel costs.
“There are a few things that we’re doing to increase that number as well, so we have new designs which are more complex,” he said.
“We expect we’ll have some initial results that look like they are performing better,” he said, but more testing is needed before they can be commercialised.
Bilinsky, with a background in physics and law, didn’t start looking for technology based specifically on microgrooves before he founded MicroTau in 2016.
MicroTau CEO Henry Bilinsky at the Sydney facility in 2022.Credit: Louise Kennerley
Applying for an open innovation challenge from the US Air Force, Bilinsky then consulted past work on drag reduction, and wondered if it could be adapted at the nanoscale, using photolithography machines, similar to those used in making microchips.
The company uses photolithography machines to produce the film which is applied to the outside of planes.
The concept of using microgrooves to cut drag in water has been around for some time. When the US won the America’s Cup back from Australia in 1987, the hull of the American yacht, The Stars & Stripes, was coated with riblets, based on NASA research. The effect underwater and in the air is similar.
“Drag is,” according to NASA, “the aerodynamic force that opposes an aircraft’s motion through the air.” It’s the aerodynamic friction. Trimming this down saves on the energy used to overcome drag.
The trick, Bilinsky says, is the “scale” of the riblets needed to reduce drag on the plane: the tiny ribs must be microscopic for them to be effective. But the scale of the production of the riblets also must be large: hundreds of square meters of the material are needed to cover a single airplane.
Importantly, the technology can be applied to existing planes, allowing large fleets to trim fuel costs. Based on current savings applied to current commercial fuel burn across the industry, it could save about $US8 billion ($12 billion) a year, and 40 billion tonnes of carbon.
The US Air Force, for example, spends $US10 billion a year on jet fuel, saving a small per cent of that bill is worthwhile. But if MicroTau technology is widely adapted, it has potential to reduce fuel bills across commercial fleets too.
Vueling is the economy airline owned by Spain-based International Airlines Group, parent company of British Airways, Iberia, and Aer Lingus among others.
Scale, scale, scale: MicroTau partnerships manager Dylan Callender holds a sample of MicroTau’s sharkskin drag reducing material.Credit: Kate Geraghty
Microtau has worked with JetStar and partnered with Delta Airlines. Vueling is the first European airline customer of MicroTau’s.
Vueling director of sustainability Franc Sanmarti said the “possibility of implementing MicroTau’s cutting-edge technology across our aircraft once it is certified marks an important milestone in Vueling’s journey toward a more sustainable aviation”.
“The original work was research done by NASA decades ago showing that if you could replicate these riblet type microstructures that you find on shark skin that it reduces friction drag,” said Bilinsky. “There are decades of research behind that principle.”
MicroTau partnerships manager Dylan Callender (left) and head of engineering Rebecca Lodin (right) install a sample of MicroTau’s sharkskin drag reducing material on a section of an Airbus aircraft. Credit: Kate Geraghty
Australian made
MicroTau is opening a larger production facility that can provide the covering for dozens of aircraft a year, with plans for a new factory next year, which will increase production.
Asked about criticism that Australia is unfavourable for manufacturing, Bilinsky noted that the staff were “highly skilled labour”, the process doesn’t involve a “huge number of hands”, Bilinsky said. Given the lightweight product, the cost of shipping is manageable.
The company has support from the NSW and federal governments through grant programs.
“I think it is still unusual to do advanced manufacturing in Australia at least in terms of the start-up world,” Bilinsky said. “I think there’s more of that happening in other countries, but I think we’re pretty bullish on doing this in the near term.”
In the longer term, if MicroTau needed to massively ramp up production, it would be open to having manufacturing plants elsewhere. The company is backed by the Clean Energy Finance Corporation’s Virescent Ventures.
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