Author: Christopher K. W. TamPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Turbulent Mixing Noise from Supersonic Jets
Author: Christopher K. W. TamOn the Two Components of Turbulent Mixing Noise from Supersonic Jets
Author: Christopher K. W. TamThe Spectrum and Directivity of Turbulent Mixing Noise from Supersonic Jets
Author: Ping ChenPublisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 238
Book Description
Location of Turbulent Mixing Noise Sources in Supersonic Jets
Author: Donnell WashingtonThe 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.
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.
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...
The Generation and Radiation of Supersonic Jet Noise: Summary of supersonic jet noise studies
Author: The Generation and Radiation of Supersonic Jet Noise: Future studies for definition of supersonic jet noise generation and reduction mechanisms
Author: Large Scale Turbulent Structures in Supersonic Jets
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781722333546
Category :
Languages : en
Pages : 34
Book Description
Jet noise is a major concern in the design of commercial aircraft. Studies by various researchers suggest that aerodynamic noise is a major contributor to jet noise. Some of these studies indicate that most of the aerodynamic jet noise due to turbulent mixing occurs when there is a rapid variation in turbulent structure, i.e. rapidly growing or decaying vortices. The objective of this research was to simulate a compressible round jet to study the non-linear evolution of vortices and the resulting acoustic radiations. In particular, to understand the effect of turbulence structure on the noise. An ideal technique to study this problem is Direct Numerical Simulations (DNS), because it provides precise control on the initial and boundary conditions that lead to the turbulent structures studied. It also provides complete 3-dimensional time dependent data. Since the dynamics of a temporally evolving jet are not greatly different from those of a spatially evolving jet, a temporal jet problem was solved, using periodicity in the direction of the jet axis. This enables the application of Fourier spectral methods in the streamwise direction. Physically this means that turbulent structures in the jet are repeated in successive downstream cells instead of being gradually modified downstream into a jet plume. The DNS jet simulation helps us understand the various turbulent scales and mechanisms of turbulence generation in the evolution of a compressible round jet. These accurate flow solutions will be used in future research to estimate near-field acoustic radiation by computing the total outward flux across a surface and determine how it is related to the evolution of the turbulent solutions. Furthermore, these simulations allow us to investigate the sensitivity of acoustic radiations to inlet/boundary conditions, with possible appli(, a- tion to active noise suppression. In addition, the data generated can be used to compute, various turbulence quantities such as mean velociti..