4 ms·
Not really; an airfoil that’s generating lift makes noise. The bigger the airfoil and the slower its moving (relative to the air stream), the less noise it crea
by falcolas 6y ago
Not really; an airfoil that’s generating lift makes noise. The bigger the airfoil and the slower its moving (relative to the air stream), the less noise it creates. However, you can’t have those characteristics with this kind of aircraft.
Multi-rotor copters like this rely on light and fast props, so that the speed of the prop can be changed quickly. This changing of the prop’s speed creates the tilting and rotational movements shown in the video.
- musingsole 6y agoThere are means: https://patents.google.com/patent/US20180305004A1/en?oq=20180305004 https://patents.google.com/patent/US20180305004A1/en?oq=2018... Blade design can also contribute or reduce noise. Fully silent while providing sufficient lift seems impossible...but how long did it take to innovate to the bladeless electric fan?
- robkop 6y agoIsn't the bladeless electric fan just a ducted bladed fan?
- slavak 6y agoNo, because "ducted fan" has a very specific meaning in aerodynamics. But yes, a bladeless electric fan isn't actually bladeless, the blades are just hidden inside the fan body. https://en.wikipedia.org/wiki/Ducted_fan https://en.wikipedia.org/wiki/Ducted_fan