scholarly journals Low‐frequency propagation across the East Greenland and Frontal Zone: Depth dependence of transmission loss

1987 ◽  
Vol 82 (S1) ◽  
pp. S31-S31
Author(s):  
Leonard E. Mellberg ◽  
D. N. Connors ◽  
D. G. Browning ◽  
G. Botseas ◽  
O. M. Johannessen
Keyword(s):  
Frontal Zone ◽  
Transmission Loss ◽  
Low Frequency ◽  
East Greenland ◽  
Depth Dependence ◽  
Zone Depth

Low‐frequency propagation across the East Greenland Frontal Zone: Directional dependence of acoustic modes

1985 ◽  
Vol 78 (S1) ◽  
pp. S71-S71
Author(s):  
Leonard E. Mellberg ◽  
Donald N. Connors ◽  
Ola M. Johannessen ◽  
George Botseas ◽  
David Browning
Keyword(s):  
Frontal Zone ◽  
Low Frequency ◽  
East Greenland ◽  
Directional Dependence ◽  
Acoustic Modes

scholarly journals An analysis of acoustic propagation across the East Greenland Frontal Zone

1985 ◽  
Vol 77 (S1) ◽  
pp. S56-S56
Author(s):  
Leonard E. Mellberg ◽  
Donald N. Connors ◽  
Ola M. Johannessen ◽  
David G. Browning ◽  
George Botseas
Keyword(s):  
Frontal Zone ◽  
Acoustic Propagation ◽  
East Greenland

Sound insulation performance of pyramidal truss core sandwich structure with frame

2021 ◽  
pp. 109963622110288
Author(s):  
Yu-Zhou Wang ◽  
Li Ma
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Transmission Loss ◽  
Low Frequency ◽  
Sound Insulation ◽  
Geometrical Parameters ◽  
Acoustic Performance ◽  
Truss Core ◽  
Pyramidal Truss ◽  
Wave Angle

Recently, sandwich structures have been widely used in different fields because of their good mechanical properties, but these structures are weak in acoustic performance. In this paper, by combining pyramidal truss core sandwich structure with frame, a new structure is proposed with both good mechanical properties and excellent acoustic performance at low frequency. An analytical model of the pyramidal truss core sandwich structure with frame is developed to investigate the sound transmission loss (STL) performance. Finite element method (FEM) is also used to investigate the STL performance at low frequency. The effects of the incident wave angle and the geometrical parameters on the STL of the structure are discussed.

Numerical study for increasement of low frequency sound insulation of double-panel structure using sonic crystals with distributed Helmholtz resonators

2019 ◽  
Vol 33 (14) ◽  
pp. 1950138
Author(s):  
Myong-Jin Kim
Keyword(s):  
Free Space ◽  
Transmission Loss ◽  
Numerical Study ◽  
Low Frequency ◽  
Helmholtz Resonator ◽  
Sound Insulation ◽  
The Finite Element Method ◽  
Helmholtz Resonators ◽  
Sonic Crystal ◽  
Sonic Crystals

Numerical simulations of the sound transmission loss (STL) of a double-panel structure (DPS) with sonic crystal (SC) comprised of distributed local resonators are presented. The Local Resonant Sonic Crystal (LRSC) consists of “C”-shaped Helmholtz resonator columns with different resonant frequencies. The finite element method is used to calculate the STL of such a DPS. First, the STLs of LRSC in free space and the DPS with LRSC are calculated and compared. It is shown that the sound insulations of the local resonators inserted in the double panel are higher than that in free space for the same size of the SCs and the same number of columns. Next, STL of the DPS in which the SC composed of three columns of local resonators having the same outer and inner diameters but different slot widths are calculated, and a reasonable arrangement order is determined. Finally, the soundproofing performances of DPS with distributed LRSC are compared with the case of insertion of general cylindrical SC for SC embedded in glass wool and not. The results show that the sound insulation of the DPS can be significantly improved in the low frequency range while reducing the total mass without increasing the thickness.

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