A series of flight tests for noise measurement was conducted by Japan Aerospace Exploration Agency using its research helicopter MuPAL-E. An onboard microphone was installed at the tip of the nose boom to obtain precise BVI (Blade-Vortex-Interaction) noise data from the main rotor. Since the characteristics of helicopter noise vary according to the flight conditions, a range of level, climbing, descending and turning flights were flown at parametrically configured airspeeds, vertical speeds, and bank angles. Strong BVI noise was measured during descending flight at airspeed of 70 knots and descent rates of 600 and 300 feet per minute. Stronger BVI noise was also measured during turning descent. A very clear waveform of the helicopter noise was obtained that will help with verifying an analytical noise model and developing noise abatement flight procedures.
In-Flight Helicopter BVI Noise Measured with Onboard External Microphone
2006
22 pages
Report
Keine Angabe
Englisch
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