Propeller sound field modification systems and methods
US9394045B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2013 |
| Grant date | Jul 19, 2016 |
| Priority date | — |
| Expiry date | Jan 3, 2035 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF05D2260/96
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A propeller system for an aircraft includes an assembly for modifying a sound field of the propeller system. The propeller system includes a rotor supported for rotation about a rotor axis. The rotor has a central hub and a plurality of blades each extending outwardly from the hub to a tip. The rotor and blades are operable to propel an aircraft to travel in a direction. The rotor blades define a rotor plane perpendicular to the rotor axis. The blade tips define a circumferential rotational path as the blades are rotated by the rotor. The propeller system includes an acoustic resonator or multiple resonators having openings disposed within a distance to the propeller blade tip that is small compared to the wavelength of the propeller's fundamental blade tone and proximate to the rotor plane. The resonators are excited by tip flow of the blade as it passes the opening. The acoustic resonators are configured and positioned so as to direct acoustic energy to modify the sound field of the propeller system at blade pass or higher harmonic frequency tones in a desired direction relative to the aircraft.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.