Author: William H. Mayes
Publisher:
ISBN:
Category :
Languages : en
Pages : 30
Book Description
Near-field and far-field noise surveys were made of the supersonic The exhaust jet of the Langley 9- by 6-foot thermal structures tunnel. The jet had a thrust rating of approximately 475,000 pounds. The sound power radiated was found to be about 3.6 x 10(exp 6) watts, and on an acoustical-mechanical efficiency basis this value is in reasonable agreement with data for smaller supersonic jets and for rocket engines of other investigations. Octave-band analyses of the near-field noise show that the maximum sound pressure levels in the low-frequency bands are greatest downstream, whereas maximum sound pressure levels in the high-frequency bands were greatest near the jet exit. A comparison of near-field noise measurements is made with data previously obtained for rocket engines. Noise survey measurements of the original jet are compared with similar data obtained after the addition of a 97-foot-long exit diffuser section, and an example of the application of this facility to the problem of acoustic environmental testing of a large space capsule is cited.
Near-Field and Far-Field Noise Measurements for a Blowdown-Wind-Tunnel Supersonic Exhaust Jet Having about 475,000 Pounds of Thrust
Author: William H. Mayes
Publisher:
ISBN:
Category :
Languages : en
Pages : 30
Book Description
Near-field and far-field noise surveys were made of the supersonic The exhaust jet of the Langley 9- by 6-foot thermal structures tunnel. The jet had a thrust rating of approximately 475,000 pounds. The sound power radiated was found to be about 3.6 x 10(exp 6) watts, and on an acoustical-mechanical efficiency basis this value is in reasonable agreement with data for smaller supersonic jets and for rocket engines of other investigations. Octave-band analyses of the near-field noise show that the maximum sound pressure levels in the low-frequency bands are greatest downstream, whereas maximum sound pressure levels in the high-frequency bands were greatest near the jet exit. A comparison of near-field noise measurements is made with data previously obtained for rocket engines. Noise survey measurements of the original jet are compared with similar data obtained after the addition of a 97-foot-long exit diffuser section, and an example of the application of this facility to the problem of acoustic environmental testing of a large space capsule is cited.
Publisher:
ISBN:
Category :
Languages : en
Pages : 30
Book Description
Near-field and far-field noise surveys were made of the supersonic The exhaust jet of the Langley 9- by 6-foot thermal structures tunnel. The jet had a thrust rating of approximately 475,000 pounds. The sound power radiated was found to be about 3.6 x 10(exp 6) watts, and on an acoustical-mechanical efficiency basis this value is in reasonable agreement with data for smaller supersonic jets and for rocket engines of other investigations. Octave-band analyses of the near-field noise show that the maximum sound pressure levels in the low-frequency bands are greatest downstream, whereas maximum sound pressure levels in the high-frequency bands were greatest near the jet exit. A comparison of near-field noise measurements is made with data previously obtained for rocket engines. Noise survey measurements of the original jet are compared with similar data obtained after the addition of a 97-foot-long exit diffuser section, and an example of the application of this facility to the problem of acoustic environmental testing of a large space capsule is cited.
NASA Technical Note
Noise Measurements During Captive and Launch Firings of a Large Rocket-powered Vehicle
Author: William H. Mayes
Publisher:
ISBN:
Category : Launch vehicles (Astronautics)
Languages : en
Pages : 40
Book Description
Publisher:
ISBN:
Category : Launch vehicles (Astronautics)
Languages : en
Pages : 40
Book Description
Acoustics Technology
Author: Skipwith W. Athey
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 152
Book Description
" ... This survey is one of a series of NASA publications that include information of interest to the non-aerospace community. In this survey, the major revival and expansion of acoustic technology that took place in the middle of this century has been reviewed. ... The information in this document is based on a comprehensive examination of the literature available on the subject. The reference material is concerned primarily with investigations of the mechanisms by which noise is generated, the propagation of noise by spacecraft boosters, the origin of noise generated by compressors in aircraft turbojet engines, and the subjective effects of noise on humans. Because many of these investigations are still in progress, the extent to which they are treated is limited in some cases. It is hoped, however, that the information presented here will stimulate interest in acoustics and the control of noise, and will guide interested persons to sources of specific information in the literature presently available."--Foreword.
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 152
Book Description
" ... This survey is one of a series of NASA publications that include information of interest to the non-aerospace community. In this survey, the major revival and expansion of acoustic technology that took place in the middle of this century has been reviewed. ... The information in this document is based on a comprehensive examination of the literature available on the subject. The reference material is concerned primarily with investigations of the mechanisms by which noise is generated, the propagation of noise by spacecraft boosters, the origin of noise generated by compressors in aircraft turbojet engines, and the subjective effects of noise on humans. Because many of these investigations are still in progress, the extent to which they are treated is limited in some cases. It is hoped, however, that the information presented here will stimulate interest in acoustics and the control of noise, and will guide interested persons to sources of specific information in the literature presently available."--Foreword.
Flow and Acoustic Characteristics of Subsonic and Supersonic Jets from Convergent Nozzle
Author: Henry T. Nagamatsu
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 90
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 90
Book Description