The sound field driven by piping systems in enclosures may severely affect living comfort,which is frequently encountered in various engineering applications.Managing this sound field relies heavily on the available p...The sound field driven by piping systems in enclosures may severely affect living comfort,which is frequently encountered in various engineering applications.Managing this sound field relies heavily on the available prediction tools at hand,e.g.,the widely used finite element methods are computationally expensive due to the necessity to discretize entire space,analytical models,based on modal expansion method,may offer substantial advantages in terms of computational cost and efficiency.However,deriving eigenmodes of irregular enclosed spaces may be challenging,which impedes accurate and rapid predictions of the sound field in practical applications.This study presents an analytical framework aimed at rapidly and accurately predicting the interior sound field driven by the piping system vibrations in irregular enclosures.Vibration response of the piping system is obtained using the wave approach,and a line dipole source is idealized as the sound source of the piping system vibration.On the basis of eigenmodes of regular enclosures,the Kirchhoff-Helmholtz integral theorem(modal ex-pansion method for irregular enclosures)is introduced to account for the boundaries of irregular enclosures.This theoretical framework is validated through numerical simulations by finite element method and experiments,demonstrating high accuracy and significant efficiency advantages.The proposed method can be further employed to optimize radiated sound fields by tailoring the impedance of space walls or layout of piping systems.This study provides an efficient tool for predicting radiated sound field in general enclosures driven by vibration of piping systems,paving a new path for indoor acoustical optimization.展开更多
A modeling method for irregular sound enclosures was proposed based on the Chebyshev-variational theory. A rectangular space was first assumed to bound the irregular sound space and the sound pressure in the rectangul...A modeling method for irregular sound enclosures was proposed based on the Chebyshev-variational theory. A rectangular space was first assumed to bound the irregular sound space and the sound pressure in the rectangular space expressed as a triple-Chebyshev series. Next, a coordinate transformation was performed and the Lagrangian functional of the irregular sound space obtained. Finally, the Lagrangian functional was solved under the Ritz method framework, and the enclosure＇s acoustic characteristic equation deduced and the eigenpairs obtained. The accuracy of the present method was validated according to agreement between the present results and finite element results for an enclosure with a curved surface.Furthermore, the acoustic characteristics of a trapezoidal enclosure and an enclosure with an inner groove were investigated. The results showed that the mode shapes of the trapezoidal sound space changed with increased inclination angle and the natural frequencies, except the first order, of the sound space with a rectangular inner groove decreased with increased groove depth.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11632003,11972083,11991030,12372088,and U22B2078)Beijing Institute of Technology Research Fund Program for Young Scholars(Grant No.XSQD-202101010).
文摘The sound field driven by piping systems in enclosures may severely affect living comfort,which is frequently encountered in various engineering applications.Managing this sound field relies heavily on the available prediction tools at hand,e.g.,the widely used finite element methods are computationally expensive due to the necessity to discretize entire space,analytical models,based on modal expansion method,may offer substantial advantages in terms of computational cost and efficiency.However,deriving eigenmodes of irregular enclosed spaces may be challenging,which impedes accurate and rapid predictions of the sound field in practical applications.This study presents an analytical framework aimed at rapidly and accurately predicting the interior sound field driven by the piping system vibrations in irregular enclosures.Vibration response of the piping system is obtained using the wave approach,and a line dipole source is idealized as the sound source of the piping system vibration.On the basis of eigenmodes of regular enclosures,the Kirchhoff-Helmholtz integral theorem(modal ex-pansion method for irregular enclosures)is introduced to account for the boundaries of irregular enclosures.This theoretical framework is validated through numerical simulations by finite element method and experiments,demonstrating high accuracy and significant efficiency advantages.The proposed method can be further employed to optimize radiated sound fields by tailoring the impedance of space walls or layout of piping systems.This study provides an efficient tool for predicting radiated sound field in general enclosures driven by vibration of piping systems,paving a new path for indoor acoustical optimization.
基金supported by the National Natural Science Foundation of China(51505237,51279035,51675286)sponsored by K.C.Wong Magna Fund in Ningbo University
文摘A modeling method for irregular sound enclosures was proposed based on the Chebyshev-variational theory. A rectangular space was first assumed to bound the irregular sound space and the sound pressure in the rectangular space expressed as a triple-Chebyshev series. Next, a coordinate transformation was performed and the Lagrangian functional of the irregular sound space obtained. Finally, the Lagrangian functional was solved under the Ritz method framework, and the enclosure＇s acoustic characteristic equation deduced and the eigenpairs obtained. The accuracy of the present method was validated according to agreement between the present results and finite element results for an enclosure with a curved surface.Furthermore, the acoustic characteristics of a trapezoidal enclosure and an enclosure with an inner groove were investigated. The results showed that the mode shapes of the trapezoidal sound space changed with increased inclination angle and the natural frequencies, except the first order, of the sound space with a rectangular inner groove decreased with increased groove depth.
