Method and device for reducing the noise of turbo-machines
US4255083A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1977 |
| Grant date | Mar 10, 1981 |
| Priority date | — |
| Expiry date | Dec 27, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S415/914
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and device for reducing the noise produced in a turbo-machine by e interaction of the blades of a ring of rotor blades and the vanes of a ring of stator vanes by the creation of a counter-noise of opposed phase. This is achieved by the injection of a fluid into the flow passage of the machine in which the blades and vanes are located. The injection is carried out through orifices located on stationary parts of the machine and equal in number to the vanes of rings of stator vanes, the flow through the orifices being modulated at the frequency of the noise to be reduced and with a phase difference which increases in an incremental manner from one orifice to the next. The phase of the modulated flows injected through the orifices is simultaneously regulated so that the acoustic waves created by the flows are substantially in opposition, with respect to phase, to those of the noise to be reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.