If you’ve ever been blasted by the downwash of a drone when it flies over you, you know how much air four spinning rotors can move. But to help improve the design and flight characteristics of future drones, NASA had its supercomputers simulate what that air movement actually looks like, and it’s impossibly complex.


The simulation, involving a 3D model of a DJI Phantom 3 quadcopter, revealed not only how air moves away from the propellers, but how it also interacts with the X-shaped craft’s body. The research, performed at NASA’s Ames Research Center, also confirmed that doubling the number of rotors nearly doubles the craft’s thrust, allowing it to lift heavier objects and making the autonomous vehicles more useful for practical applications—and not just filming vacation videos.