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The exposed propellers found on many unmanned aircraft systems pose substantial hazards. People can easily cut themselves on the sharp, exposed motors. Bladeless drones would eliminate that risk to operators as well as to the environment around them.
Texas A&M University-Corpus Christi graduate student Daniel Valdenegro wanted to make drones safer to fly by creating a propulsion system inspired by Dyson’s bladeless fan design.
Valdenegro went to work on the project with the help of Assistant Professor of Electrical Engineering Luis Rodolfo Garcia Carrillo.
“In a sense, this is like a quadcopter but with a completely different propulsion system,” Garcia Carrillo said. “The blades are all internal. That makes it much more challenging to develop than a conventional quadcopter, but it also makes it much safer, which is the ultimate goal.”
Bladeless fan cross-section geometry, airflow properties, impellers, motors, ducted fans and conventional quadcopter dynamic modeling were all used in the propulsion system’s design. Based on their research into bladeless fan design, the team of four developed a nozzle that attaches to an Electric Ducted Fan (EDF) to create a bladeless thruster prototype, according to insideunmannedsystems.com.
The team has completed two tests so far. “We wanted to test to see if it could be controlled in four degrees of freedom, which is how a drone moves in aerospace,” Valdenegro said. “We found out it could be controlled and we did that by creating thrusters and a platform that looks like a UAV. We put it on a tripod because we could move the tripod in all directions, like how a drone moves. We wanted to test how all those movements combined would affect the drone and if it could be controlled. We had a good result and are getting closer to it flying.”
The main challenge is the fact the rotors are all internal rather than outside the system. Instead of spinning in a vertical plane like a typical quadcopter, the thrusters all spin horizontally, creating a different dynamic.
While there’s enough power to control the vehicle and move it in different directions, the team hasn’t been able to generate enough thrust to achieve lift, Valdenegro said.
In addition to safety, the system is easy to manipulate, even by non-expert users.
The drone could also be used for pushing objects. If you tried that with a drone equipped with traditional propellers, you’d end up damaging the object or the drone, but that’s not the case with this system. “If you want to push an object with a drone you have to add a manipulator and structure for doing the pushing, and this affects the dynamic of the system because you’re adding something external,” Carrillo said. “A bladeless propulsion system can push with its own body.”
For the time being, the team has to get the prototype flying. While they’re always finding new challenges to overcome, they hope to make that happen by the end of the year. They’re also in the process of submitting a patent and forming an LLC. “Now we’re trying to maximize thrust so it can fly, and we can see how it will behave in aerospace.”