|Drone (Marvin® quadcopter)
|BLDC outrunner (12 stator slots and 7 pole pairs)
|Run-up at no-load under non sinusoidal supply
|Electromagnetic (no blades)
Noise is measured 40 cm from the quadcopter on the floor. Blades are removed from the 4 propeller motors to only record electromagnetically-excited noise. The motors are accelerated up to maximum speed. Torque level is very small due to missing aerodynamic load (only friction load).
Sound file and spectrograms
Sound of UAV propeller motors (quadcopter without blades)
Note: these sound files are the property of EOMYS; for authorized use in presentations, website, publications or technical work, please contact us
This sound file illustrates electromagnetically-excited noise of a BLDC high speed motor nearly in open circuit conditions (armature current close to 0). High pitch whining noise is due to resonances between pole/slot electromagnetic excitations and the outer rotor structural modes. This experiments shows that a significant part of the sound of UAVs (Unmanned Aerial Vehicles) is due to electromagnetic noise.
Application to MANATEE
MANATEE software can be used to quickly calculate NVH due to electromagnetic forces both in early design and detailed design phase, including PWM and slotting effects.