New type rotor blade to challenge the helicopter's difficult enemy "noise"

The mobility of helicopters is used in various fields regardless of military or civilian use, but due to the mechanism of breaking the air with a huge blade to generate lift, the noise becomes bigger than anything but weak point is.

So it seems that European helicopter manufacturer developed rotor blades to suppress noise. As long as you listen to the sound of the movie actually measured, it seems quite possible that the noise is getting smaller enough to make it clear.

Details are below.
Eurocopter Moves One Step Closer to 'Whisper Mode' | Autopia | Wired.com

This "blue edge" rotor blade was developed by the European largest helicopter manufacturerEurocopter. The special shape of the blade end reduces the occurrence of air vortices due to blade rotation and reduces the generation of noise due to interference between vortexes.

Moreover, by "blue pulse" technology, by moving the flap of the rear part of the blade automatically 15 to 40 times per second, it reduces the periodic slap sound frequently heard when descending and combines it with the blue edge blade, We succeeded in suppressing 4 decibels.

At the company,We are planning to develop a helicopter with a fuel-efficient diesel engine, Blue Edge blade will also be adopted for this helicopter. We are trying to aim for environmentally friendly helicopter from noise and fuel efficiency.

A movie about how you can hear it when you recorded with the conditions is also released.

Test machine'sEC 155It is like this when measuring from inside the aircraft. This is the sound for ordinary rotor blades. "Papapapapapa ......" It is high pitched sound quality with waves.
YouTube - Eurocopter Blue Edge rotor blade noise reduction


When it is a blue edge it will look something like this. "Droodorodoro ......" It changed into a sound quality with a small amount of muffled sound.


This is the case when measuring from the ground. This is the sound for ordinary rotor blades. Although it was lower than in the cabin, the regular pulse sound "Bababababa ......" stands out.


When it is a blue edge it will look something like this. It feels like hearing the sound of the jumbo jet in the distance. There are obvious differences.


"Green" is often used as a term expressing environmental measures in the US area, but in Europe, environmentalism "Greens"Has a certain force, Volkswagen's"Blue motion"Or" Mercedes-Benz AG "Blue Efficiency"Blue" is often used for environmental countermeasures technology.

By the way, a masterpiece helicopter action movie released in 1983 "Blue ThunderA helicopter that adopts "whisper mode" will erase the rotor sound, but the base of the aircraft that appears in the play is the one of Aerospasearal, the predecessor of Eurocopter. Is this naming just a coincidence, or is there a developer who understands Sharet inside Eurocopter, is not interested.