3 ms·
How much of the noise of a helicopter is from the sonic booms of the rotor tips? I read somewhere it’s a substantial portion but I may be misremembering.
by jack_riminton 3y ago
How much of the noise of a helicopter is from the sonic booms of the rotor tips? I read somewhere it’s a substantial portion but I may be misremembering.
- 0x0203 3y agoVery little, and rarely, if I understand correctly. The characteristic thwop-thwop noise of many helicopters is from the blade passing through the vortex created by the previous blade. In some circumstances, this might lead to local and intermittent supersonic flow, but it's not typical. I think it also only happens when the vehicle is moving in a particular way, but I don't know how vortices propagate from a rotor blade, so I couldn't say how or when the supersonic flow is most likely to occur.