Realizing a finite array of dipole sources with high acoustic transmission directivity at low frequency

2017 ◽  
Vol 141 (3) ◽  
pp. 1936-1939 ◽  
Author(s):  
Erliang Ding ◽  
Yiwei Mao ◽  
Xiaozhou Liu
Keyword(s):  
Low Frequency ◽  
Acoustic Transmission ◽  
Dipole Sources

Prediction of High Frequency Sonic Boom Noise Transmission Into Buildings Using a Hybrid Analytical-Ray Tracing Approach

2012 ◽  
Author(s):  
Joseph M. Corcoran ◽  
Marcel C. Remillieux ◽  
Ricardo A. Burdisso
Keyword(s):  
Ray Tracing ◽  
High Frequency ◽  
Acoustic Radiation ◽  
Low Frequency ◽  
Sonic Boom ◽  
Acoustic Transmission ◽  
Frequency Method ◽  
Low Frequencies ◽  
Sonic Booms ◽  
Acoustic Responses

As part of the effort to renew commercial supersonic flight, a predictive numerical tool to compute sonic boom transmission into buildings is under development. Due to the computational limitations of typical numerical methods used at low frequencies (e.g. Finite Element Method), it is necessary to develop a separate approach for the calculation of acoustic transmission and interior radiation at high frequencies. The high frequency approach can then later be combined with a low frequency method to obtain full frequency vibro-acoustic responses of buildings. An analytical method used for the computation of high frequency acoustic transmission through typical building partitions is presented in this paper. Each partition is taken in isolation and assumed to be infinite in dimension. Using the fact that a sonic boom generated far from the structure will approximate plane wave incidence, efficient analytical solutions for the vibration and acoustic radiation of different types of partitions are developed. This is linked to a commercial ray tracing code to compute the high frequency interior acoustic response and for auralization of transmitted sonic booms. Acoustic and vibration results of this high frequency tool are compared to experimental data for a few example cases demonstrating its efficiency and accuracy.

Realization of Subwavelength Asymmetric Acoustic Transmission Based on Low-Frequency Forbidden Transmission

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Sai Zhang ◽  
Yu Zhang ◽  
Yijun Guo ◽  
Yanhong Leng ◽  
Wen Feng ◽  
...  
Keyword(s):  
Low Frequency ◽  
Acoustic Transmission

Acoustic Transmission of Low-frequency Sounds

1985 ◽  
Vol 62 (6) ◽  
pp. 814-815 ◽  
Author(s):  
GREGG A. KORBON
Keyword(s):  
Low Frequency ◽  
Acoustic Transmission

Whistler radiation in plasmas with cylindrical magnetic field irregularities

2009 ◽  
Vol 76 (2) ◽  
pp. 193-207 ◽  
Author(s):  
C. KRAFFT ◽  
T. M. ZABORONKOVA
Keyword(s):  
Magnetic Field ◽  
Laboratory Experiments ◽  
Low Frequency ◽  
Wave Radiation ◽  
Whistler Waves ◽  
Frequency Wave ◽  
Ambient Magnetic Field ◽  
Physical Conditions ◽  
Local Perturbations ◽  
Dipole Sources

AbstractThe radiation of whistler waves by linear dipole sources immersed in magnetoplasmas with cylindrical magnetic field inhomogeneities are studied. Two types of irregularities are investigated: magnetic field enhancements and depletions. A theoretical analysis is developed for comparatively weak local perturbations of the ambient magnetic field. Results are provided by numerical calculations performed for physical conditions typical of laboratory experiments involving artificially created magnetic field irregularities. It is shown that plasma regions with locally enhanced (depleted) magnetic field intensities can increase (decrease) the amplitudes of whistler waves radiated by dipole sources, regardless of their orientation with respect to the ambient magnetic field. Results are relevant to space and laboratory experiments on very low-frequency wave radiation.

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