Why We Use Jets to Power Helicopters #VeritasiumContest
Channel: Marcin Anforowicz
Date: 2021-07-18

#VeritasiumContest
By: Marcin Anforowicz (10th grader)   manforowicz@gmail.com

Partonez - Helicopter Image https://commons.wikimedia.org/wiki/File:Coastguard_Rescue_Helicopter_at_Corbyn_Head_(3).jpg

Tom Stanton - His great YouTube videos introduced me to the concept of air powered propellers. https://www.youtube.com/user/tomstanton282

---Software (All free & open source)---
OS: MX Linux
Audio: Audacity
Graphics: Inkscape
Animation: Synfig
Editing: Kdenlive

--Transcript--
Inside a turbine helicopter, a jet engine blows a turbine causing it to spin. This turbine mechanically rotates the large rotor that lifts the helicopter.

Why not remove all that, and just point the jet straight down? Wouldn’t this direct propulsion be more efficient? No.

Imagine you’re in space, and need to accelerate to 10 m/s by jumping off a light ball, or off a heavy space station.

Jumping off of which object requires the least strength to reach this speed?

In both cases, both objects will get an equal kick of momentum. However, the heavy space station will gain a lot less speed and kinetic energy than the light ball. Jumping to a certain speed off the heavier object takes less work since you don’t need to give it as much kinetic energy.

The helicopter’s jet pushes little air, very fast. But a large rotor spun by it can push lots of air, very slowly. And pushing lots of air very slowly requires giving it much less energy.