Author: Jay C. Hardin
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 36
Book Description
Effects of Temperature-profile Variation on Refraction of Sound by Jet Flow
Author: Jay C. Hardin
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 36
Book Description
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 36
Book Description
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 628
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 628
Book Description
Refraction of Sound by Jet Flow and Jet Temperature Ii
Author: E. Grande
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The refraction of the sound field of an omnidirectional pure tone 'point' source of sound by the temperature and velocity fields of a 3/4 inch air or nitrogen jet was measured. Several source positions were employed: one within the potential core, others entirely outside the jet. For the source in the on-axis position, the air jet velocity was varied between M = 0.5 and 0.95 at fixed source frequency and ambient jet temperature, yielding a characteristic axial refraction valley, e.g., -35dB at M = 0.95 and 3000 c.p.s. Similar, but asymmetric patterns were obtained with the source outside the jet. Using a very cold nitrogen jet (T = -180C), the sound was found to be refracted inward - a focusing effect - to yield an intensity lobe along the jet axis; e.g. +26dB at M = 0.11 and 7000 c.p.s. For both the cold jet and the ambient jet the ordinary jet noise was measured in narrow filter bands: the respective polar plots exhibited the same general shape near the axis as those for the injected pure tones. The filtered jet noise polar plots were also 'corrected' for refraction (using the pure-tone patterns) and for convection (via theory) to yield the approximate 'basic directivity' of the eddy sources: the polar patterns resemble ellipses of low eccentricity, rather unlike Lighthill's four-leaf-clover. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The refraction of the sound field of an omnidirectional pure tone 'point' source of sound by the temperature and velocity fields of a 3/4 inch air or nitrogen jet was measured. Several source positions were employed: one within the potential core, others entirely outside the jet. For the source in the on-axis position, the air jet velocity was varied between M = 0.5 and 0.95 at fixed source frequency and ambient jet temperature, yielding a characteristic axial refraction valley, e.g., -35dB at M = 0.95 and 3000 c.p.s. Similar, but asymmetric patterns were obtained with the source outside the jet. Using a very cold nitrogen jet (T = -180C), the sound was found to be refracted inward - a focusing effect - to yield an intensity lobe along the jet axis; e.g. +26dB at M = 0.11 and 7000 c.p.s. For both the cold jet and the ambient jet the ordinary jet noise was measured in narrow filter bands: the respective polar plots exhibited the same general shape near the axis as those for the injected pure tones. The filtered jet noise polar plots were also 'corrected' for refraction (using the pure-tone patterns) and for convection (via theory) to yield the approximate 'basic directivity' of the eddy sources: the polar patterns resemble ellipses of low eccentricity, rather unlike Lighthill's four-leaf-clover. (Author).
Refraction of Sound by Jet Flow Or Jet Temperature
Author: University of Toronto. Institute for Aerospace Studies
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 772
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 772
Book Description
Refraction of Sound by Jet Flow and Jet Temperature
Author: E. Grande
Publisher:
ISBN:
Category : Jet plane sounds
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Jet plane sounds
Languages : en
Pages :
Book Description
Publications in Acoustic and Noise Control from NASA Langley Research Center During 1940-1979
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 110
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 110
Book Description
Publications in Acoustics and Noise Control from the NASA Langley Research Center During 1940 - 1974
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 76
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 76
Book Description
The Aeronautical Journal
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 612
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 612
Book Description
Monthly Catalogue, United States Public Documents
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1730
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1730
Book Description