scholarly journals Vibro-Acoustic Energy Transmission Analysis of the Acoustic Cavity with Multiple Partial Partitions

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2257
Author(s):  
Yufei Zhang ◽  
Jingtao Du ◽  
Yang Liu
Keyword(s):  
Sound Intensity ◽  
Acoustic Energy ◽  
Sound Insulation ◽  
Coupling Mechanism ◽  
Energy Transmission ◽  
Energy Principle ◽  
Acoustic Coupling ◽  
Acoustic Cavity ◽  
Coupling System ◽  
Partial Partitions

The general dynamic characteristics of the acoustic cavity with multiple partial partitions are presented in this thesis. A theoretical model has been developed for predictions, and several configurations are analyzed. To describe the apertures on the interface of subcavities, the virtual air panel assumption is introduced into the improved Fourier series system. The governing equations of the coupling system are derived by using the energy principle. The results obtained with the proposed model are firstly compared with the numerical calculations based on the finite element method (FEM). Subsequently, a configuration made up from a rigid cavity partitioned by a partial steel panel has been specifically built, and the forced responses of the coupling system have been measured for comparison and model validation. The present results are excellent over most of the studied frequency range. Furthermore, the visualizations of the interior sound intensity field of the acoustic cavity with three partial partitions under different frequencies are researched to illustrate the energy transmission paths and vibro-acoustic coupling mechanism of the complicated system. The obtained results are believed to be helpful in the optimal design of the vibro-acoustic coupling system with optimal sound insulation capacity.

scholarly journals Vibro-acoustic coupling characteristics of orthotropic L-shaped plate–cavity coupling system

2019 ◽  
Vol 39 (4) ◽  
pp. 1102-1126
Author(s):  
Dongyan Shi ◽  
Wenhui Ren ◽  
Hong Zhang ◽  
Gai Liu ◽  
Qingshan Wang
Keyword(s):  
Boundary Conditions ◽  
Sound Pressure ◽  
Future Research ◽  
Response Analysis ◽  
Acoustic Coupling ◽  
Acoustic Cavity ◽  
Coupling System ◽  
Cavity Coupling ◽  
Coupling Characteristics ◽  
Admissible Functions

The research object of this paper is the L-shaped plate–cavity coupling system established by a cuboid acoustic cavity with rigid-wall or impedance-wall and L-shaped plate with numerous elastic boundary conditions in view of the Fourier series method. The main research content of this paper is the vibro-acoustic coupling characteristics. In this paper, the displacements admissible functions of the L-shaped plate are generally set as the sum of two cosines’ product and two polynomials. Sound pressure admissible functions of the cuboid acoustic cavity can be considered as the sum of three cosines’ product and six polynomials. The discontinuity of coupling system at all boundaries in the overall solution domain is overcome in this way. Through the energy principle and the Rayleigh-Ritz technology, it can be got that the solving matrix equation of the L-shaped plate-cavity coupling system. Based on verifying the great numerical characteristics of the L-shaped plate–cavity coupling model, they obtained both the frequency analysis and the displacement or sound pressure response analysis under the excitation, including a unit simple harmonic force or a unit monopole source. The advantages of this method are parameterization and versatility. In addition, some new achievements have been shown, based on various materials, boundary conditions, thicknesses, and orthotropic degrees, which may become the foundation for the future research.

scholarly journals Analysis of Tire Acoustic Cavity Resonance Energy Transmission Characteristics in Wheels Based on Power Flow Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3979
Author(s):  
Wei Zhao ◽  
Yuting Liu ◽  
Xiandong Liu ◽  
Yingchun Shan ◽  
Xiaojun Hu
Keyword(s):  
Power Flow ◽  
Resonance Energy ◽  
Cavity Resonance ◽  
Propagation Path ◽  
Material Structure ◽  
Transmission Characteristics ◽  
Energy Transmission ◽  
Flow Method ◽  
Acoustic Cavity ◽  
Power Flow Method

As a kind of low-frequency vehicle interior noise, tire acoustic cavity resonance noise plays an important role, since the other noise (e.g., engine noise, wind noise and friction noise) has been largely suppressed. For the suspension system, wheels stand first in the propagation path of this energy. Therefore, it is of great significance to study the influence of wheel design on the transmission characteristics of this vibration energy. However, currently the related research has not received enough attention. In this paper, two sizes of aluminum alloy wheel finite element models are constructed, and their modal characteristics are analyzed and verified by experimental tests simultaneously. A mathematically fitting sound pressure load model arising from the tire acoustic cavity resonance acting on the rim is first put forward. Then, the power flow method is applied to investigate the resonance energy distribution and transmission characteristics in the wheels. The structure intensity distribution and energy transmission efficiency can be described and analyzed clearly. Furthermore, the effects of material structure damping and the wheel spoke number on the energy transmission are also discussed.

Structural Source Identification from Acoustic Measurements Using an Energetic Approach

2017 ◽  
Vol 34 (4) ◽  
pp. 431-441 ◽  
Author(s):  
A. Samet ◽  
M. A. Ben Souf ◽  
O. Bareille ◽  
M. N. Ichchou ◽  
T. Fakhfakh ◽  
...  
Keyword(s):  
Energy Method ◽  
Numerical Test ◽  
Acoustic Energy ◽  
Vibration Source ◽  
Radiated Noise ◽  
Acoustic Cavity ◽  
Energetic Approach ◽  
Structural Force ◽  
Noise Measurements ◽  
Acoustic Energy Density

AbstractAn inverse energy method for the identification of the structural force in high frequency ranges from radiated noise measurements is presented in this paper. The radiation of acoustic energy of the structure coupled to an acoustic cavity is treated using an energetic method called the simplified energy method. The main novelty of this paper consists in using the same energy method to solve inverse structural problem. It consists of localization and quantification of the vibration source through the knowledge of acoustic energy density. Numerical test cases with different measurement points are used for validation purpose. The numerical results show that the proposed method has an excellent performance in detecting the structural force with a few acoustical measurements.

MEMS microphone intensity array for cabin noise measurements

2021 ◽  
Vol 263 (3) ◽  
pp. 3023-3034
Author(s):  
Carsten Spehr ◽  
Daniel Ernst ◽  
Hans-Georg Raumer
Keyword(s):  
Sound Intensity ◽  
Phase Match ◽  
Acoustic Energy ◽  
Low Frequencies ◽  
Cabin Noise ◽  
Noise Simulation ◽  
Mems Microphone ◽  
Noise Measurements ◽  
Mems Microphones ◽  
Absorbing Material

Aircraft cabin noise measurements in flight are used toto quantify the noise level, and to identify the entry point of acoustic energy into the cabin. Sound intensity probes are the state-of-the-art measurement technique for this task. During measurements, additional sound absorbing material is used to ease the rather harsh acoustic measurement environment inside the cabin. In order to decrease the expensive in-flight measurement time, an intensity array approach was chosen. This intensity probe consists of 512 MEMS-Microphones. Depending on the frequency, these microphones can be combined as an array of hundreds of 3D- intensity probes. The acoustic velocity is estimated using a high order 3D finite difference stencil. At low frequencies, a larger spacing is used to reduce the requirement of accurate phase match of the microphone sensors. Measurements were conducted in the ground-based Dornier 728 cabin noise simulation as well as in-flight.

Mediation of acoustic energy transmission from acoustic wave sensors to the liquid phase by interfacial viscosity

1991 ◽  
Vol 63 (6) ◽  
pp. 615-621 ◽  
Author(s):  
Ljubinka V. Rajakovic ◽  
Biljana A. Cavic-Vlasak ◽  
Vida. Ghaemmaghami ◽  
Krishna M. R. Kallury ◽  
Arlin L. Kipling ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Acoustic Wave ◽  
Acoustic Energy ◽  
Energy Transmission ◽  
Acoustic Wave Sensors ◽  
Wave Sensors

scholarly journals Sound Radiation from an Elastically Restrained Plate Covered by an Acoustic Decoupling Layer

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Gang Wang ◽  
Wan-You Li ◽  
Wen Long Li ◽  
Jingtao Du
Keyword(s):  
Sound Radiation ◽  
Sound Field ◽  
Sound Intensity ◽  
Parametric Modeling ◽  
Model Studies ◽  
Coupling System ◽  
Ritz Procedure ◽  
Reduction Effect ◽  
Elastically Restrained ◽  
Sound Reduction

The sound radiation from elastically restrained plates covered by a decoupling layer is studied using the Spectrogeometric Method (SGM), which is a meshless and parametric modeling technique. By adopting the Rayleigh-Ritz procedure and the Rayleigh integral, a vibroacoustic coupling system is established. This model studies the situation when the plate is immersed in heavy fluid, such as water, in which the strong coupling between the structure and sound field should be fully considered. The influence of the boundary conditions on the radiated sound power and sound reduction provided by the decoupling layer based on the locally reacting model is studied. The nonuniform distributed decoupling layer is also studied to analyze the sound reduction effect. The sound intensity on the outer surface of the decoupling layer is investigated and tends to be uniform along the plate scale with increasing thickness of the decoupling layer.

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