The Experts below are selected from a list of 37665 Experts worldwide ranked by ideXlab platform

Qiuwang Wang - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on the flow noise propagation mechanism in simple expansion pipelines based on synergy principle of flow and Sound Fields
    Energy Procedia, 2017
    Co-Authors: Hanbing Ke, Min Zeng, Qiuwang Wang
    Abstract:

    Abstract The noise pollution in pipelines exists for a long time and can’t be ignored in modern industries. It is important to investigate the transfer mechanism of Sound energy in pipelines and develop high efficiency mufflers with low penalty of pressure drop. Different with the traditional method, this study is focused on the flow and Sound Fields synergy principle to investigate the flow noise propagation mechanism in reactive mufflers. In this study, theoretical analysis and numerical simulation methods are coupled to investigate the noise propagation process. In the theoretical analysis aspect, the synergetic relationships between the flow and pressure gradient Fields are deduced and the field synergy theory is established. In the numerical simulation aspect, the flow noise propagation process in the simple expansion chamber mufflers is studied. The results show that with the decrease of synergy between flow and Sound Fields, the work done by the fluid on the wall decreases, which means the exchange of Sound energy between the wall and the fluid decreases.

  • Investigation on the flow noise propagation mechanism in pipelines of shell-and-tube heat exchangers based on synergy principle of flow and Sound Fields
    Applied Thermal Engineering, 2017
    Co-Authors: Hanbing Ke, Min Zeng, Qiuwang Wang
    Abstract:

    Abstract As major equipment for implementing technological process, Shell-and-Tube Heat Exchangers are widely used in modern industries. Because the noise propagation in pipelines in shell-and-tube heat exchangers can’t be ignored, it is a key point to investigate the transfer mechanism of Sound energy in pipelines and develop high efficiency mufflers with low penalty of pressure drop. Different with the traditional method, this study is focused on the flow and Sound Fields synergy principle to investigate the flow noise propagation mechanism in pipelines. In this study, theoretical analysis and numerical simulation methods are coupled to investigate the pipeline noise propagation process. Based on the momentum and the energy equations in the Sound field, the synergetic relationship between the flow field and the pressure gradient field is deduced, and the field synergy theory is established. The flow noise propagation process of noise in the pipeline is studied by numerical simulation. The synergy is verified by analyzing the calculating results of flow and Sound Fields. The results show that with the increase of synergy between flow and Sound Fields, the work done by the fluid on the wall increases, which means the exchange of Sound energy between the wall and the fluid increases.

Xiao-zheng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • real time separation of non stationary Sound Fields with pressure and particle acceleration measurements
    Journal of the Acoustical Society of America, 2014
    Co-Authors: Lin Geng, Xiao-zheng Zhang
    Abstract:

    To extract the desired non-stationary Sound field generated by a target source in the presence of disturbing sources, a real-time Sound field separation method with pressure and particle acceleration measurements is proposed. In this method, the pressure and particle acceleration signals at a time instant are first measured on one measurement plane, where the particle acceleration is obtained by the finite difference approximation with the aid of an auxiliary measurement plane; then, the desired pressure signal generated by the target source at the same time instant can be extracted in a timely manner, by a simple superposition of the measured pressure and the convolution between the measured particle acceleration and the derived impulse response function. Thereby, the proposed method possesses a significant feature of real-time separation of non-stationary Sound Fields, which provides the potential to in situ analyze the radiation characteristics of a non-stationary source. The proposed method was examined through numerical simulation and experiment. Results demonstrated that the proposed method can not only extract the desired time-evolving pressure signal generated by the target source at any space point, but can also obtain the desired spatial distribution of the pressure field generated by the target source at any time instant.

  • reconstruction of nonstationary Sound Fields based on the time domain plane wave superposition method
    Journal of the Acoustical Society of America, 2012
    Co-Authors: Xiao-zheng Zhang, Jean-hugh Thomas, Jean-claude Pascal
    Abstract:

    A time-domain plane wave superposition method is proposed to reconstruct nonstationary Sound Fields. In this method, the Sound field is expressed as a superposition of time convolutions between the estimated time-wavenumber spectrum of the Sound pressure on a virtual source plane and the time-domain propagation kernel at each wavenumber. By discretizing the time convolutions directly, the reconstruction can be carried out iteratively in the time domain, thus providing the advantage of continuously reconstructing time-dependent pressure signals. In the reconstruction process, the Tikhonov regularization is introduced at each time step to obtain a relevant estimate of the time-wavenumber spectrum on the virtual source plane. Because the double infinite integral of the two-dimensional spatial Fourier transform is discretized directly in the wavenumber domain in the proposed method, it does not need to perform the two-dimensional spatial fast Fourier transform that is generally used in time domain holography and real-time near-field acoustic holography, and therefore it avoids some errors associated with the two-dimensional spatial fast Fourier transform in theory and makes possible to use an irregular microphone array. The feasibility of the proposed method is demonstrated by numerical simulations and an experiment with two speakers.

  • Reconstruction of nonstationary Sound Fields based on time domain plane wave superposition method
    2012
    Co-Authors: Xiao-zheng Zhang, Jean-hugh Thomas, Jean-claude Pascal
    Abstract:

    A new time-domain plane wave superposition method (TD-PWSM) is proposed to reconstruct nonstationary Sound Fields. At each time step of this method, the time-wavenumber spectrum of the Sound pressure on the virtual source plane is firstly estimated by using the measured Sound pressure and the right pseudo-inverse of the time-domain propagation kernel matrix, and then the reconstruction is performed through a superposition of all the time convolutions between the estimated time-wavenumber spectrum of the Sound pressure on the virtual source plane and the time-domain propagation kernel at each wavenumber. Since the inverse process at each time step is ill-conditioned, the Tikhonov regularization is introduced to obtain an appropriate solution. The method proposed provides the ability of continuously reconstructing time-dependent pressure signals and overcomes some errors due to the use of the two-dimensional spatial Fourier transforms, which is avoided. Numerical simulations and an experiment demonstrate that it is feasible to reconstruct the nonstationary Sound Fields via TD-PWSM.

  • Separation of nonstationary Sound Fields in the time-wavenumber domain.
    Journal of the Acoustical Society of America, 2012
    Co-Authors: Xiao-zheng Zhang, Jean-hugh Thomas, Chuan-xing Bi, Jean-claude Pascal
    Abstract:

    A number of Sound field separation techniques have been proposed for different purposes. However, these techniques just consider the separation of Sound Fields in the space domain and are restricted to stationary Sound Fields. When the Sound Fields are nonstationary, it is also necessary to perform the separation in the time domain. Therefore, on the basis of the propagation principle of Sound pressure in the time-wavenumber domain, a nonstationary Sound field separation technique with two closely spaced parallel measurement surfaces is proposed. It can separate the nonstationary signals generated by the primary sources in both time and space domains when the disturbing sources exist on the other side of the measurement plane. The signals in time and space domains are separated by using the spatial Fourier transform method and the time domain deconvolution method. A simulation involving two monopoles driven by nonstationary signals demonstrates that the method proposed can remove the influence of disturbi...

Jean-claude Pascal - One of the best experts on this subject based on the ideXlab platform.

  • reconstruction of nonstationary Sound Fields based on the time domain plane wave superposition method
    Journal of the Acoustical Society of America, 2012
    Co-Authors: Xiao-zheng Zhang, Jean-hugh Thomas, Jean-claude Pascal
    Abstract:

    A time-domain plane wave superposition method is proposed to reconstruct nonstationary Sound Fields. In this method, the Sound field is expressed as a superposition of time convolutions between the estimated time-wavenumber spectrum of the Sound pressure on a virtual source plane and the time-domain propagation kernel at each wavenumber. By discretizing the time convolutions directly, the reconstruction can be carried out iteratively in the time domain, thus providing the advantage of continuously reconstructing time-dependent pressure signals. In the reconstruction process, the Tikhonov regularization is introduced at each time step to obtain a relevant estimate of the time-wavenumber spectrum on the virtual source plane. Because the double infinite integral of the two-dimensional spatial Fourier transform is discretized directly in the wavenumber domain in the proposed method, it does not need to perform the two-dimensional spatial fast Fourier transform that is generally used in time domain holography and real-time near-field acoustic holography, and therefore it avoids some errors associated with the two-dimensional spatial fast Fourier transform in theory and makes possible to use an irregular microphone array. The feasibility of the proposed method is demonstrated by numerical simulations and an experiment with two speakers.

  • Reconstruction of nonstationary Sound Fields based on time domain plane wave superposition method
    2012
    Co-Authors: Xiao-zheng Zhang, Jean-hugh Thomas, Jean-claude Pascal
    Abstract:

    A new time-domain plane wave superposition method (TD-PWSM) is proposed to reconstruct nonstationary Sound Fields. At each time step of this method, the time-wavenumber spectrum of the Sound pressure on the virtual source plane is firstly estimated by using the measured Sound pressure and the right pseudo-inverse of the time-domain propagation kernel matrix, and then the reconstruction is performed through a superposition of all the time convolutions between the estimated time-wavenumber spectrum of the Sound pressure on the virtual source plane and the time-domain propagation kernel at each wavenumber. Since the inverse process at each time step is ill-conditioned, the Tikhonov regularization is introduced to obtain an appropriate solution. The method proposed provides the ability of continuously reconstructing time-dependent pressure signals and overcomes some errors due to the use of the two-dimensional spatial Fourier transforms, which is avoided. Numerical simulations and an experiment demonstrate that it is feasible to reconstruct the nonstationary Sound Fields via TD-PWSM.

  • Separation of nonstationary Sound Fields in the time-wavenumber domain.
    Journal of the Acoustical Society of America, 2012
    Co-Authors: Xiao-zheng Zhang, Jean-hugh Thomas, Chuan-xing Bi, Jean-claude Pascal
    Abstract:

    A number of Sound field separation techniques have been proposed for different purposes. However, these techniques just consider the separation of Sound Fields in the space domain and are restricted to stationary Sound Fields. When the Sound Fields are nonstationary, it is also necessary to perform the separation in the time domain. Therefore, on the basis of the propagation principle of Sound pressure in the time-wavenumber domain, a nonstationary Sound field separation technique with two closely spaced parallel measurement surfaces is proposed. It can separate the nonstationary signals generated by the primary sources in both time and space domains when the disturbing sources exist on the other side of the measurement plane. The signals in time and space domains are separated by using the spatial Fourier transform method and the time domain deconvolution method. A simulation involving two monopoles driven by nonstationary signals demonstrates that the method proposed can remove the influence of disturbi...

Thushara D Abhayapala - One of the best experts on this subject based on the ideXlab platform.

  • real time separation of non stationary Sound Fields on spheres
    Journal of the Acoustical Society of America, 2019
    Co-Authors: Wen Zhang, Thushara D Abhayapala
    Abstract:

    The Sound field separation methods can separate the target field from the interfering noises, facilitating the study of the acoustic characteristics of the target source, which is placed in a noisy environment. However, most of the existing Sound field separation methods are derived in the frequency-domain, thus they are best suited for separating stationary Sound Fields. In this paper, a time-domain Sound field separation method is developed that can separate the non-stationary Sound field generated by the target source over a sphere in real-time. A spherical array sets up a boundary between the target source and the interfering sources, such that the outgoing field on the array is only generated by the target source. The proposed method decomposes the pressure and the radial particle velocity measured by the array into spherical harmonic coefficients, and recovers the target outgoing field based on the time-domain relationship between the decomposition coefficients and the theoretically derived spatial filter responses. Simulations show the proposed method can separate non-stationary Sound Fields both in free field and room environments, and over a longer duration with small errors. The proposed method could serve as a foundation for developing future time-domain spatial Sound field manipulation algorithms.

  • Real-time separation of non-stationary Sound Fields on spheres.
    Journal of the Acoustical Society of America, 2019
    Co-Authors: Fei Ma, Wen Zhang, Thushara D Abhayapala
    Abstract:

    The Sound field separation methods can separate the target field from the interfering noises, facilitating the study of the acoustic characteristics of the target source, which is placed in a noisy environment. However, most of the existing Sound field separation methods are derived in the frequency-domain, thus they are best suited for separating stationary Sound Fields. In this paper, a time-domain Sound field separation method is developed that can separate the non-stationary Sound field generated by the target source over a sphere in real-time. A spherical array sets up a boundary between the target source and the interfering sources, such that the outgoing field on the array is only generated by the target source. The proposed method decomposes the pressure and the radial particle velocity measured by the array into spherical harmonic coefficients, and recovers the target outgoing field based on the time-domain relationship between the decomposition coefficients and the theoretically derived spatial filter responses. Simulations show the proposed method can separate non-stationary Sound Fields both in free field and room environments, and over a longer duration with small errors. The proposed method could serve as a foundation for developing future time-domain spatial Sound field manipulation algorithms.The Sound field separation methods can separate the target field from the interfering noises, facilitating the study of the acoustic characteristics of the target source, which is placed in a noisy environment. However, most of the existing Sound field separation methods are derived in the frequency-domain, thus they are best suited for separating stationary Sound Fields. In this paper, a time-domain Sound field separation method is developed that can separate the non-stationary Sound field generated by the target source over a sphere in real-time. A spherical array sets up a boundary between the target source and the interfering sources, such that the outgoing field on the array is only generated by the target source. The proposed method decomposes the pressure and the radial particle velocity measured by the array into spherical harmonic coefficients, and recovers the target outgoing field based on the time-domain relationship between the decomposition coefficients and the theoretically derived spatial ...

  • 2 5d multizone reproduction with active control of scattered Sound Fields
    International Conference on Acoustics Speech and Signal Processing, 2019
    Co-Authors: Junqing Zhang, Wen Zhang, Thushara D Abhayapala, Jingli Xie, Lijun Zhang
    Abstract:

    Multizone reproduction has been focused on reproducing Sounds in an empty listening space. However, there are always scatterers such as human heads in Sound zones, generating scattered Sound Fields and causing degraded system performance. In this work, we develop a modal-domain method for 2.5D multizone reproduction with a solid object in the bright zone. Analytical expressions of the incident and scattered Fields are developed. We then propose an active control strategy to correct the scattering effect. In the reproduction stage, we use the weighted mode matching approach to achieve the optimal control over the entire region. Simulation results show that in comparison with the conventional method which does not consider the scattering effect, the proposed method can achieve higher acoustic contrast performance over a broadband frequency range.

Hanbing Ke - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on the flow noise propagation mechanism in simple expansion pipelines based on synergy principle of flow and Sound Fields
    Energy Procedia, 2017
    Co-Authors: Hanbing Ke, Min Zeng, Qiuwang Wang
    Abstract:

    Abstract The noise pollution in pipelines exists for a long time and can’t be ignored in modern industries. It is important to investigate the transfer mechanism of Sound energy in pipelines and develop high efficiency mufflers with low penalty of pressure drop. Different with the traditional method, this study is focused on the flow and Sound Fields synergy principle to investigate the flow noise propagation mechanism in reactive mufflers. In this study, theoretical analysis and numerical simulation methods are coupled to investigate the noise propagation process. In the theoretical analysis aspect, the synergetic relationships between the flow and pressure gradient Fields are deduced and the field synergy theory is established. In the numerical simulation aspect, the flow noise propagation process in the simple expansion chamber mufflers is studied. The results show that with the decrease of synergy between flow and Sound Fields, the work done by the fluid on the wall decreases, which means the exchange of Sound energy between the wall and the fluid decreases.

  • Investigation on the flow noise propagation mechanism in pipelines of shell-and-tube heat exchangers based on synergy principle of flow and Sound Fields
    Applied Thermal Engineering, 2017
    Co-Authors: Hanbing Ke, Min Zeng, Qiuwang Wang
    Abstract:

    Abstract As major equipment for implementing technological process, Shell-and-Tube Heat Exchangers are widely used in modern industries. Because the noise propagation in pipelines in shell-and-tube heat exchangers can’t be ignored, it is a key point to investigate the transfer mechanism of Sound energy in pipelines and develop high efficiency mufflers with low penalty of pressure drop. Different with the traditional method, this study is focused on the flow and Sound Fields synergy principle to investigate the flow noise propagation mechanism in pipelines. In this study, theoretical analysis and numerical simulation methods are coupled to investigate the pipeline noise propagation process. Based on the momentum and the energy equations in the Sound field, the synergetic relationship between the flow field and the pressure gradient field is deduced, and the field synergy theory is established. The flow noise propagation process of noise in the pipeline is studied by numerical simulation. The synergy is verified by analyzing the calculating results of flow and Sound Fields. The results show that with the increase of synergy between flow and Sound Fields, the work done by the fluid on the wall increases, which means the exchange of Sound energy between the wall and the fluid increases.