Author: Christopher K. W. TamPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
On the Two Components of Turbulent Mixing Noise from Supersonic Jets
Author: Christopher K. W. TamTurbulent Mixing Noise from Supersonic Jets
Author: Christopher K. W. TamThe Generation and Radiation of Supersonic Jet Noise
Author: H. K. TannaPublisher:
ISBN:
Category : Jet planes
Languages : en
Pages : 0
Book Description
The characteristics, both spectral and directivity, of the sound field of supersonic shock-free jets are studied by measuring the turbulent mixing noise in the far field from four two-inch diameter nozzles, namely a convergent nozzle for pressure ratios up to critical and three convergent- divergent nozzles having nominal design Mach numbers of 1.4, 1.7, and 2.0, respectively. The measurements were conducted in a free-field environment. The results from 75 jet exit conditions are presented in a systematic manner in the form of tabulated one-third octave spectra. The test program was carefully planned in order to obtain results (i) at constant jet efflux temperature with varying jet velocity, and conversely (ii) at constant exit velocity while varying jet efflux temperature. The effects of jet velocity and exhaust temperature on turbulent mixing noise can therefore be assessed independently.
Location of Turbulent Mixing Noise Sources in Supersonic Jets
Author: Donnell WashingtonThe Spectrum and Directivity of Turbulent Mixing Noise from Supersonic Jets
Author: Ping ChenPublisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 238
Book Description
The Generation and Radiation of Supersonic Jet Noise. Volume 3. Turbulent Mixing Noise Data
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 471
Book Description
The characteristics, both spectral and directivity, of the sound field of supersonic shock-free jets are studied by measuring the turbulent mixing noise in the far field from four two-inch diameter nozzles, namely a convergent nozzle for pressure ratios up to critical and three convergent- divergent nozzles having nominal design Mach numbers of 1.4, 1.7, and 2.0, respectively. The measurements were conducted in a free-field environment. The results from 75 jet exit conditions are presented in a systematic manner in the form of tabulated one-third octave spectra. The test program was carefully planned in order to obtain results (i) at constant jet efflux temperature with varying jet velocity, and conversely (ii) at constant exit velocity while varying jet efflux temperature. The effects of jet velocity and exhaust temperature on turbulent mixing noise can therefore be assessed independently.
The Generation and Radiation of Supersonic Jet Noise. Volume 4. Shock-Associated Noise Data
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 416
Book Description
The characteristics of the sound field of shock-containing under- expanded jets are studied by measuring the noise from a two-inch diameter convergent nozzle over an extensive envelope of supercritical jet operating conditions. The measurements, which are accurate and comprehensive, were conducted in the Lockheed anechoic facility. The results are presented in this Volume in a systematic manner in the form of narrowband spectra. The details pertinent to the experimental program and the data presentation format are summarized below. The total noise spectrum from an incorrectly expanded jet flow contains discrete components (or screech) in addition to the basic turbulent mixing noise and the broadband shock-associated noise. In order to study the trends and dependencies of the broadband component accurately, it is vital to keep the contamination by screech to a minimum in the experimental program. In the present experiments, screech suppression was successfully achieved by wrapping all surfaces surrounding the nozzle exit with sound absorbing material, and incorporating a small projection inside the nozzle lip. This projection interrupts the feedback loop between the first shock and the nozzle exit plane, which has been previously proposed and verified as the physical mechanism of screech generation. The detailed calibration tests, conducted prior to the main shock-associated noise experiments, established that all results are essentially uncontaminated by the presence of screech.
Jet Aeroacoustics
Author: National Aeronautics and Space Adm NasaPublisher: Independently Published
ISBN: 9781792791574
Category :
Languages : en
Pages : 34
Book Description
Progress associated with research in (1) physics and prediction of turbulent mixing noise from supersonic jets, and (2) numerical simulation of supersonic jet noise is reported. Tam, Christopher Langley Research Center NASA-CR-203579, NAS 1.26:203579 NAG1-1776...
Author: 
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