Supersonic jet noise source distributions
نویسندگان
چکیده
The purpose of this work is to examine the noise source distributions shock-containing supersonic jets at various pressure ratios corresponding fully expanded Mach numbers ranging from 1.0 1.4 in intervals 0.2 for nozzle exit diameters. Source location measurements using a phased array (beamforming), farfield jet measurements, and schlieren flow visualization are presented. It found that more complex than those subsonic jets. can be divided into three different Strouhal regions. At low (fD/U≤0.3), appear very similar jet, as reported open literature. This region dominated by jet-mixing associated with small-scale turbulence mixing. high (fD/U≥1.0), comprised several repetitive sources discrete downstream locations produce all frequencies. these roughly correspond shock cells thus, vary number. Another exists between two regions (0.3<fD/U<1.0) which precise function number was determined ambiguous due limitation used. corresponds frequencies where levels. spacing smaller beam width measuring them. Their no longer separately recorded; instead, they averaged together their centroid plotted.
منابع مشابه
Wavepacket models for supersonic jet noise
Gudmundsson and Colonius (J. Fluid Mech., vol. 689, 2011, pp. 97–128) have recently shown that the average evolution of low-frequency, low-azimuthal modal large-scale structures in the near field of subsonic jets are remarkably well predicted as linear instability waves of the turbulent mean flow using parabolized stability equations. In this work, we extend this modelling technique to an isoth...
متن کاملMach Wave Noise of a Supersonic Jet
Supersonic jets emit noise to the outside in form of Mach waves which are long, straight and have about equal angles. Experiments done by Oertel sen. visualized clearly these Mach waves and he publicized moreover that such Mach waves exist also inside the jet. Experimental and theoretical studies in the past did not allow a complete understanding of the phenomenon up to now, wherefore the need ...
متن کاملSimulation of Supersonic Military Aircraft Jet Noise
Background: There is a growing need to reduce significantly the noise generated by high-performance, supersonic military aircraft. The noise generated during takeoff and landing on aircraft carriers has direct impact on shipboard health and safety issues. Also, noise complaints are increasing as communities move closer to military bases or when there are changes due to base closures and realign...
متن کاملNear - Field Noise Computation for a Supersonic Circular Jet
A fully expanded, high-Reynolds-number, supersonic circular jet of Mach number 1.4 is simulated, using a 3-D finite-volume NavierStokes solver, with emphasis on the near field noise. The numerical results are generally in good agreement with existing experimental findings.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of the Acoustical Society of America
سال: 2021
ISSN: ['0001-4966', '1520-9024', '1520-8524']
DOI: https://doi.org/10.1121/10.0006381