Epistemic Review

Confidence: 51%

Sources

To-do

Small propeller diameter + high rotational speed of propeller blade tip → intense high-frequency pressure waves

Large propeller diameters + slower blade tip rotational speed → impulsive low-frequency pressure waves

Intensity and frequency

  • Propeller diameter controls noise intensity
  • Propeller speed controls noise frequency
  • [?] How does wingspan affect noise? Greater wingspan increases contact area with air molecules, thus increasing noise

  • Paper on BLI ducted fans for reducing noise in eVTOLs

  • Joby Aviation is making eVTOLs that produce less noise (~50 dBA)