Drones are more and more in the news, whether it’s the government deploying them to spy on citizens or companies like Amazon exploring ways to use them to deliver packages. Because they’re getting so popular, you may have seen your friends showing off their drones and wondered, how drones fly? The physics of how these unmanned aerial vehicles (UAVs) stay aloft can be complicated, but this guide will explain all you need to know about how quadcopters fly and stay up in the air.
Why is flying a drone so different from flying an airplane?
Most people understand how airplanes fly because it’s the same principle that has been used for over a hundred years. Airplanes use lifts to fly. However, how drones fly is quite different. Drones use rotors to create lift and thrust to stay in the air and move forward. This design makes drones more maneuverable than airplanes, but also more susceptible to wind and other weather conditions. A drone relies on four things to stay in the air:
1) angular momentum;
2) propellers spinning up or down;
These principles can be understood through Newton’s third law: every action has an equal and opposite reaction. For example, when you want your drone to accelerate upwards or downwards, you would spin your propellers downward or upward respectively. And since propellers are tilted at an angle with respect to the ground their blades actually move backward relative to their centerline direction of motion while they are spinning. The backward movement creates an additional horizontal force that causes lift – this is how drones fly!
Basic Principles of Flight
How do drones fly? It’s a question with a surprisingly simple answer: they use rotors. But why rotors, and not wings like most commercial planes? Why can’t you just strap some jet engines onto a box and call it a day?
A couple of things are at play here. Firstly, rotors are inherently more efficient than jet engines for this application; the high-speed spinning blades in each rotor provide much more thrust than any gas turbine engine could hope to match for such an application.
Why Most Commercial Planes Use Wings Instead of Rotors
If you’ve ever wondered how drones fly, you’re not alone. These devices have only become commonplace in the last few years, and yet they’re already advanced enough that anyone can fly them. So how do these flying machines stay in the air? It all has to do with the aerodynamics of quadcopters.
Multirotor drones take advantage of Bernoulli’s principle to stay in the air. This principle states that as the speed of a fluid increases, the pressure within that fluid decreases. When applied to quadcopters, this means that as the rotors spin faster, they create less lift and the drone begins to fall.
To counteract this, the drone’s flight controller adjusts the speed of each rotor so that they are all spinning at the same rate. This maintains a consistent level of lift and keeps the drone in the air.
What About Quadcopter Physics?
To understand how a quadcopter flies, you first need to understand a little bit about the physics of flight. An airplane’s wings create lift by deflecting air downward, which in turn pushes the plane upward. A helicopter’s rotor blades work similarly, except that they push air downward in a rotating motion.
A quadcopter has four rotors, which gives it more control over its flight than a helicopter. Each rotor creates lift by pushing air downward, and the quadcopter can change the direction of its flight by changing the speed at which each rotor is spinning.
Newtons Second Law Applied to Quadcopters
When a force acts on an object, how drones fly causes that object to accelerate. The acceleration produced by the force is directly proportional to the magnitude of the force and inversely proportional to the mass of the object. This means that if you double the force acting on an object, the object will accelerate twice as much. Conversely, if you double the mass of an object, the acceleration will be cut in half.
In physics, this is known as the Law of Conservation of Momentum. It states that for every action there’s an equal and opposite reaction; what goes up must come down (or at least change direction). When most people think about how something stays up in the air, they only think about an aerodynamic lift.
In reality, two forces are responsible for how objects stay airborne: gravity and thrust/lift. Gravity applies a downward force to the object while thrust pushes upward against gravity—producing lift against gravity.