When will DJI Drones incorporate Toroidal Propellers?
TL;DR – Toroidal propellers are an innovative design that saves energy and, for aerial use, potentially increase acceleration and manoeuvrability. Prototypes using DJI drones and Toroidal propellers already exist.
Aerial drones have revolutionized various industries, such as agriculture, mapping, defence, and film production. However, their use in recreational and sporting activities has also increased in recent years, with hobbyists seeking drones with improved performance, speed, and manoeuvrability. DJI is a leading company in the consumer-grade drone market, and its products have features such as obstacle avoidance, GPS location, and high-quality cameras. Despite these advancements, drone propellers have not seen much development, and there are opportunities to use toroidal propellers that enhance drone performance for sporting and recreational use.
How They Work
Toroidal propellers significantly reduce tip vortices and this increases the volume of air/water that moves in a useful direction ie through the blade rather than wasted by slipping off the edges
https://twitter.com/MITLL/status/1611438712683958306
Toroidal propellers are unique in their design, with a circular shape for each ‘fin’. This design creates a vortex that provides an additional lift for the same power input, allowing the drone to achieve a longer battery life, quieter operation and greater manoeuvrability.
Caveats
This technology probably won’t work for aeroplane jet turbines that already include design elements to stop wasted air at the fin tips.
The image below shows a standard propeller protection mechanism, if your drone has been specifically designed (not retrofitted) with something like this then the savings from toroidal props might not be as good. (IDK the exact nature of this but it will be a factor)
Toroidal propellers will almost certainly also change handling characteristics. As human controllers you can no doubt adapt to that change, however, pre-defined manufacturer algorithms such as those for obstacle avoidance might not do so well.
Thoughts
A few years ago my thoughts strayed to capturing drone footage of me cycling up some alpine trails. It never got any further than the thought stage!
I came across toroidal propellers by accident after ones by MIT won a global design award in 2022 (R&D 100). They were invented decades ago but it seems that they are only now approaching the point where they might start to be more widely used.
When we sometimes think that everything that could be easily invented has been, it’s uplifting (pun intended) that a simple, new 3D-printed design can make a 20% difference to a drone’s battery life with the added bonus of quieter operation.
Propellers are obviously used elsewhere and this technology could reduce fuel consumption on container ships, propeller-based planes or even your desktop PC’s fans. Of course, the militarily minded will make more lethal drones. There’s always a downside.
This is interesting. Given the recent developments in the Russian invasion, I’d rather not make drones more quiet and lethal – since it has direct implications, but in general for using drones for civilian purposes (and there are, I think, even more than military ones), this is a good development.
IS IT possible to buy your drone propellers anywhere?
i think you can get them 3d printed. i don’t know much more than that
Just so people don’t expect too much and aren’t disappointed if they 3D print toroidal propellers, there are a few things to remember.
Rough surfaces will drastically reduce the effectiveness of any propeller. Thick sections will also be less effective. Heavier props like the big circles shown in one of the pictures above will not work well. And they are a horrible design for efficiency. They were obviously an early prototype at MIT, not the final design. The circles are tragically unaerodynamic and have a horrid lift to drag ratio, though they will be quieter. Some probably due to lower rpm from the extra helping of drag.
The best one is a much straighter version of the top picture with actual wing shape cross-section. The big round loops make a large part of the prop do no lifting at all.