Noise reduction system

Patent metadata

Field	Value
Publication number	US-9528468-B2
Application number	US-201013504195-A
Country	US
Kind code	B2
Filing date	Oct 26, 2010
Priority date	Oct 28, 2009
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A noise reduction system includes: a microjet ring ( 16 ) provided at an exhaust side peripheral edge of a main nozzle of a jet engine, and has a plurality of injection pipes ( 26 ) formed in a circumferential direction thereof at regular intervals; and a supply path configured to take part of compressed air in from a flow path in an upstream side of a combustor in the jet engine, and to guide the part of compressed air to the plurality of injection pipes ( 26 ), wherein the plurality of injection pipes ( 26 ) is configured to inject the part of compressed air to a jet flow.

First claim

What is claimed is:

1. A noise reduction system comprising:
a microjet ring provided at an exhaust side peripheral edge of a main nozzle of a jet engine, and has a plurality of injection pipes formed in a circumferential direction thereof at regular intervals; and
a supply path configured to take part of compressed air in from a flow path in an upstream side of a combustor in the jet engine, and to guide the part of compressed air to the plurality of injection pipes, wherein
the plurality of injection pipes is configured to inject the part of compressed air to a jet flow exhausted from the main nozzle,
the microjet ring is formed so as to be gradually reduced in diameter from an upstream side toward a downstream side of the jet flow,
an arc surface is formed at a tip, in the downstream side of the jet flow, of the microjet ring so that the arc surface connects an inner peripheral surface and an outer peripheral surface of the microjet ring,
the whole of the arc surface increases in diameter from the upstream side toward the downstream side of the jet flow,
a point where the arc surface intersects the inner peripheral surface of the microjet ring is located where a diameter of the inner peripheral surface of the microjet ring is a minimum,
a surface of each of the plurality of injection pipes intersects the arc surface at the point where the arc surface intersects the inner peripheral surface of the microjet ring, and
openings of the plurality of injection pipes are provided in the arc surface.

2. The noise reduction system according to claim 1 , wherein
at least a vicinity of an injection outlet side in the plurality of injection pipes is formed toward the downstream side of the jet flow so that an acute angle is formed between the vicinity and an axial direction of the main nozzle.

3. The noise reduction system according to claim 1 , wherein
a chamber is provided between the microjet ring and the flow path, and configured to communicate the microjet ring to the flow path.

Assignees

• Tanaka Nozomi
• Kusuda Shinya
• Oishi Tsutomu
• Oba Yoshinori
• Ihi Corp

Inventors

• Tanaka Nozomi
• Kusuda Shinya
• Oishi Tsutomu
• Oba Yoshinori

Classifications

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F02K1/52

  Nozzles specially constructed for positioning adjacent to another nozzle or to a fixed member, e.g. fairing · CPC title

• F02K1/38

  Introducing air inside the jet (F02K1/28 takes precedence) · CPC title

• F02C6/08

  the gas being bled from the gas-turbine compressor · CPC title

• F02K1/34 Primary

  for attenuating noise · CPC title