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Recent topics on aerodynamic noise; Kuriki soon ni kansuru saikin no wadai

Journal Article:

Abstract

For measures to deal with aerodynamic noise, recent subjects were put in order and some examples of the studies were introduced in this paper. Aerodynamic noise can be classified into rotational aerodynamic noise such as jet engine fans or helicopter rotors and general aerodynamic noise such as high speed jet noise, high speed air flow inside piping, and external noise from vehicles, cars and aeroplanes. The aerodynamic noise of the air flow radiated from a wind tunnel exit was caused more or less by the pressure fluctuation of a boundary layer in a high frequency wave region. In checking the noise generated from a difference in level, projection, cavity, opening, etc., of a high speed vehicle in a wind tunnel test, the noise was louder in the case of a difference in level where the downstream side was raised. The finding was similar with projections. In the rear of a super sonic choke part, a strong flow was generated and became a violent noise source when a flow was overexpanded and a pressure was recovered with a sonic boom. However, the noise was greatly reduced by installing a porous material such as a porous metal immediately behind the choke part.  More>>
Authors:
Nishimura, M [1] 
  1. Mitsubishi Heavy Industries Ltd., Tokyo (Japan)
Publication Date:
Apr 20, 1995
Product Type:
Journal Article
Report Number:
CONF-9505301-
Reference Number:
SCA: 560400; 320200; 320303; PA: NEDO-95:912939; EDB-96:010756; SN: 96001506877
Resource Relation:
Journal Name: Jidosha Gijutsukai Gakujutsu Koenkai Maezurishu; Journal Issue: 953; Conference: 1995 JSAE (Society of Automotive Engineers of Japan Inc.)`s spring conference, JSAE 1995 nen shunki taikai gakujutsu koenkai, Yokohama (Japan), 16-18 May 1995; Other Information: PBD: 20 Apr 1995
Subject:
56 BIOLOGY AND MEDICINE, APPLIED STUDIES; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; NOISE POLLUTION; AERODYNAMICS; NOISE POLLUTION CONTROL; BLOWERS; TURBOJET ENGINES; TURBOFAN ENGINES; JETS; VEHICLES; AIRCRAFT; AIR FLOW; HELICOPTERS; BOUNDARY LAYERS; ROUGHNESS; CONFIGURATION; CONTRACTION; SUPERSONIC FLOW; SHOCK WAVES; POROUS MATERIALS; FILLERS; RESONANCE; EXCITATION
OSTI ID:
148129
Country of Origin:
Japan
Language:
Japanese
Other Identifying Numbers:
Journal ID: JGGMD8; ISSN 0919-1364; TRN: 95:912939
Submitting Site:
NEDO
Size:
pp. 1-4
Announcement Date:

Journal Article:

Citation Formats

Nishimura, M. Recent topics on aerodynamic noise; Kuriki soon ni kansuru saikin no wadai. Japan: N. p., 1995. Web.
Nishimura, M. Recent topics on aerodynamic noise; Kuriki soon ni kansuru saikin no wadai. Japan.
Nishimura, M. 1995. "Recent topics on aerodynamic noise; Kuriki soon ni kansuru saikin no wadai." Japan.
@misc{etde_148129,
title = {Recent topics on aerodynamic noise; Kuriki soon ni kansuru saikin no wadai}
author = {Nishimura, M}
abstractNote = {For measures to deal with aerodynamic noise, recent subjects were put in order and some examples of the studies were introduced in this paper. Aerodynamic noise can be classified into rotational aerodynamic noise such as jet engine fans or helicopter rotors and general aerodynamic noise such as high speed jet noise, high speed air flow inside piping, and external noise from vehicles, cars and aeroplanes. The aerodynamic noise of the air flow radiated from a wind tunnel exit was caused more or less by the pressure fluctuation of a boundary layer in a high frequency wave region. In checking the noise generated from a difference in level, projection, cavity, opening, etc., of a high speed vehicle in a wind tunnel test, the noise was louder in the case of a difference in level where the downstream side was raised. The finding was similar with projections. In the rear of a super sonic choke part, a strong flow was generated and became a violent noise source when a flow was overexpanded and a pressure was recovered with a sonic boom. However, the noise was greatly reduced by installing a porous material such as a porous metal immediately behind the choke part. An active control of noise was carried out by changing a sound field characteristic against aerodynamic self-excited noise with a speaker. 32 refs., 11 figs.}
journal = {Jidosha Gijutsukai Gakujutsu Koenkai Maezurishu}
issue = {953}
journal type = {AC}
place = {Japan}
year = {1995}
month = {Apr}
}