Scientists in Finland are testing new solutions to prevent drone wings and engine blades from freezing in freezing conditions, in an effort to keep them airborne even in the coldest months. In winter, drone flights are limited due to cold temperatures, fog, rain or snow, which can cover drones in ice, causing malfunctions and crashes. The risk to drones is highest in temperatures between -8°C and -10°C, according to drone pilots and experts. A thin layer of ice forms on propellers and wings and disrupts aerodynamics. At a research lab in Finland, aerodynamics engineer Joachim Wallisch, who works for Norwegian startup Ubiq Aerospace, is trying to solve this problem.
“It’s important that drones don’t get stuck in ice, because ice on a drone reduces performance. It can reduce stability, but it can also lead to crashes. So that’s what we try to limit with our system, limit the performance degradation and a drone can fly in icy conditions.”
Only the larger, longer-range models have enough power for anti-icing systems like those used by airplanes. Traditional methods of preventing aircraft wings or propellers from freezing are too energy-intensive for smaller, battery-powered drones. For smaller drones with limited battery power, flying them without using too much power was essential. “It’s important to have an optimal system for the drone, especially in terms of using as little power as possible, because these drones usually don’t have a lot of power to spare. So every watt we get out of the system is probably going to reduce the drone’s flight time. So every watt we can save with our system is kind of a win for us and also for the drone operator at the end of the day.”
One approach Ubiq is testing is to add a carbon fiber mesh that can be ignited to conduct enough heat to the wing to melt any ice buildup.
“So the ultimate goal with these wings is that we just put some heat on and then we can remove all the ice from the wing. We hope to learn how to best design an ice protection system so that it can work across multiple different designs, so that it uses as little energy as possible to completely remove the ice from the wing.” During the tests, Wallisch places a section of a drone wing equipped with a prototype heating system, a carbon fiber mesh with a layer of fiberglass on top to protect it, inside the element.
When Wallisch activates the net, part of the ice melts within seconds.
“So what we can clearly see here are these kinds of ice streams. It happens when as we heat the ice we melt a little bit of it. When the rest of it flies away, we have the water flowing back and then it just freezes further downstream. That’s one of the main things we’re working on to reduce that. Another thing we can see here is that there’s a little bit of ice and that shows there’s still an edge. We’ll have to do more testing to see what it is.”
The work, carried out at Ubiq, reflects a broader trend among commercial drone manufacturers aiming to sell to the militaries of NATO member countries by making their products robust enough to operate in extreme environments and optimizing energy use.
