Use of flow injection and extraction to control blade vortex interaction and high speed impulsive noise in helicopters
US6283406A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1999 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Sep 10, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T50/30
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An active control device for reducing high-speed impulsive ("HSI") and blade vortex interaction ("BVI") noise in a rotor aircraft, such as a helicopter, is disclosed. The system comprises a plurality of rotor blades extending radially in spaced relationship from a central hub, each of the blades having spaced apart upper and lower surfaces, an interior volume between the surfaces, and leading and trailing edges at the respective joined edges of the upper and lower surfaces. Air intake passages are disposed on the surfaces of each blade proximate the leading edge to controllably admit air into the interior volume; and air output passages are disposed on the surfaces of each blade proximate the trailing edge and the outer edge tip to controllably expel air from the interior volume of the blade. Admitting and expelling of air into and out of the interior volume of each blade is controlled in accordance with a determined condition of that blade. When the presence of BVI or HSI noise, or any condition giving rise to such noise, is sensed, the admittance and expulsion of air is activated to minimize the noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.