How does a rotor blade work?
Unlike airplanes, helicopters feature spinning wings called blades or rotors on top. As a helicopter’s blades spin, they create a force called lift that allows the helicopter to rise into the air. The rear rotor can face different directions, allowing the helicopter to move forward, backward, and sideways.
How does whisper mode on helicopter work?
The noise is created when a rotor blade hits the wake vortex left behind from the blade in front of it. You can listen to a cockpit recording of Eurocopter’s EC155 with and without the Blue Edge rotor below. Normally, the entire length of the rotor blade interacts with the vortex of the preceding blade.
How does a helicopter rotor system work?
Fully articulated rotor systems are found on helicopters with more than two main rotor blades. As the rotor spins, each blade responds to inputs from the control system to enable aircraft control. The center of lift on the whole rotor system moves in response to these inputs to effect pitch, roll, and upward motion.
Do helicopters really have whisper mode?
Nope, like a Star Trek Phaser, Whisper Mode is a fictional device. The 1980s cinematic masterpiece features a helicopter made by what is now Eurocopter, an Aérospatiale Gazelle. And one of the helicopter’s most impressive technologies was its “whisper mode” that allowed it to fly around as quiet as a glider.
Do helicopters have quiet mode?
And helicopters can be more or less quiet in certain flight conditions, such as during an approach. This is due to blade vortex interaction (BVI), a type of loading noise. Each main rotor blade also produces a strong tip vortex whose trajectory travels downstream from the rotor in an approximately epicyclical manner.
How does blue edge rotors work on Eurocopter?
With the Blue Edge rotors, the double-swept tips of the rotor blade reduce the length of the blade-vortex interaction, and it does it at the tip where the blades are moving the fastest relative to the air. The result is a decrease in the sound produced due of the wake interaction at the tip.
What kind of technology does a Eurocopter use?
In addition to the Blue Edge rotor blade, the company also introduced something called Blue Pulse technology. Also designed to reduce helicopter noise, the Blue Pulse system uses three flap modules in the trailing edge of each rotor blade.
What makes the pulsating noise on a Eurocopter?
Blade-vortex interaction is the source of the pulsating sound most of us are familiar with when helicopters fly overhead. The noise is created when a rotor blade hits the wake vortex left behind from the blade in front of it. You can listen to a cockpit recording of Eurocopter’s EC155 with and without the Blue Edge rotor below.
How does Blue Pulse system reduce helicopter noise?
Also designed to reduce helicopter noise, the Blue Pulse system uses three flap modules in the trailing edge of each rotor blade. Piezoelectric motors move actuate the flaps 15 to 40 times per second in reduce the “slap noise” often heard when a helicopter is descending.