Based on the coupled acoustic scattering of two neighboring fluid-filled thin elastic shells suspending in an unbounded viscous liquid,an analytical method is developed to calculate the acoustic radiation force(ARF)of...Based on the coupled acoustic scattering of two neighboring fluid-filled thin elastic shells suspending in an unbounded viscous liquid,an analytical method is developed to calculate the acoustic radiation force(ARF)of the shells.Two physical effects are taken into account:elastic radiation scattering and the multiple interactions of shells.Numerical results reveal that the magnitude of ARF can be enhanced by the sound radiation from the elastic shell undergoing forced vibrations and two resonant peaks can be observed on the ARF function curves.The feature of the lower peak is determined by the interactions and acoustic response of the back shell.The attractive forces can be obtained in the low kR1 band for the case of radius ratio R2/R1>1,while the magnitude of ARF at the lower peak may be influenced to some extent by acoustic shielding phenomenon for the case of radius ratio R2/R1<1.Accordingly,the interactions of particles cannot be ignored.The results may provide a theoretical basis for precisive manipulation of multiple particle systems.展开更多
This paper mainly discusses the development status of solar radiation measurement technology,it expounds the relevant content of the current world radiation measurement datum and its standardization. Article the direc...This paper mainly discusses the development status of solar radiation measurement technology,it expounds the relevant content of the current world radiation measurement datum and its standardization. Article the direct radiation from the sun,the main measuring principle of total radiation and scattering radiation,this paper discusses the different types of radiation survey measuring elements,measuring range,emphasis and the current widespread use of measurement instruments. The development trend of future solar radiation measurement is put forward,and it is emphasized that nanotechnology and spectrum technology will become the focus of solar radiation instrument research and development.展开更多
This paper proposes amodified formulation of the singular boundarymethod(SBM)by introducing the combined Helmholtz integral equation formulation(CHIEF)and the self-regularization technique to exterior acoustics.In the...This paper proposes amodified formulation of the singular boundarymethod(SBM)by introducing the combined Helmholtz integral equation formulation(CHIEF)and the self-regularization technique to exterior acoustics.In the SBM,the concept of the origin intensity factor(OIF)is introduced to avoid the singularities of the fundamental solutions.The SBM belongs to the meshless boundary collocation methods.The additional use of the CHIEF scheme and the self-regularization technique in the SBM guarantees the unique solution of the exterior acoustics accurately and efficiently.Consequently,by using the SBM coupled with the CHIEF scheme and the self-regularization technique,the accuracy of the numerical solution can be improved,especially near the corresponding internal characteristic frequencies.Several numerical examples of two-dimensional and threedimensional benchmark examples about exterior acoustics are used to verify the effectiveness and accuracy of the proposed method.The proposed numerical results are compared with the analytical solutions and the solutions obtained by the other numerical methods.展开更多
The application of wavelets is explored to solve acoustic radiation and scattering problems. A new wavelet approach is presented for solving two-dimensional and axisymmetric acoustic problems. It is different from the...The application of wavelets is explored to solve acoustic radiation and scattering problems. A new wavelet approach is presented for solving two-dimensional and axisymmetric acoustic problems. It is different from the previous methods in which Galerkin formulation or wavelet matrix transform approach is used. The boundary quantities are expended in terms of a basis of the periodic, orthogonal wavelets on the interval. Using wavelet transform leads a highly sparse matrix system. It can avoid an additional integration in Galerkin formulation, which may be very computationally expensive. The techniques of the singular integrals in two-dimensional and axisymmetric wavelet formulation are proposed. The new method can solve the boundary value problems with Dirichlet, Neumann and mixed conditions and treat axisymmetric bodies with arbitrary boundary conditions. It can be suitable for the solution at large wave numbers. A series of numerical examples are given. The comparisons of the results from new approach with those from boundary element method and analytical solutions demonstrate that the new techique has a fast convergence and high accuracy.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974232,11727813,11474191,and 11474192).
文摘Based on the coupled acoustic scattering of two neighboring fluid-filled thin elastic shells suspending in an unbounded viscous liquid,an analytical method is developed to calculate the acoustic radiation force(ARF)of the shells.Two physical effects are taken into account:elastic radiation scattering and the multiple interactions of shells.Numerical results reveal that the magnitude of ARF can be enhanced by the sound radiation from the elastic shell undergoing forced vibrations and two resonant peaks can be observed on the ARF function curves.The feature of the lower peak is determined by the interactions and acoustic response of the back shell.The attractive forces can be obtained in the low kR1 band for the case of radius ratio R2/R1>1,while the magnitude of ARF at the lower peak may be influenced to some extent by acoustic shielding phenomenon for the case of radius ratio R2/R1<1.Accordingly,the interactions of particles cannot be ignored.The results may provide a theoretical basis for precisive manipulation of multiple particle systems.
文摘This paper mainly discusses the development status of solar radiation measurement technology,it expounds the relevant content of the current world radiation measurement datum and its standardization. Article the direct radiation from the sun,the main measuring principle of total radiation and scattering radiation,this paper discusses the different types of radiation survey measuring elements,measuring range,emphasis and the current widespread use of measurement instruments. The development trend of future solar radiation measurement is put forward,and it is emphasized that nanotechnology and spectrum technology will become the focus of solar radiation instrument research and development.
基金supported by the National Science Fund of China(Grant No.12122205)the Six Talent Peaks Project in Jiangsu Province of China(Grant No.2019-KTHY-009).
文摘This paper proposes amodified formulation of the singular boundarymethod(SBM)by introducing the combined Helmholtz integral equation formulation(CHIEF)and the self-regularization technique to exterior acoustics.In the SBM,the concept of the origin intensity factor(OIF)is introduced to avoid the singularities of the fundamental solutions.The SBM belongs to the meshless boundary collocation methods.The additional use of the CHIEF scheme and the self-regularization technique in the SBM guarantees the unique solution of the exterior acoustics accurately and efficiently.Consequently,by using the SBM coupled with the CHIEF scheme and the self-regularization technique,the accuracy of the numerical solution can be improved,especially near the corresponding internal characteristic frequencies.Several numerical examples of two-dimensional and threedimensional benchmark examples about exterior acoustics are used to verify the effectiveness and accuracy of the proposed method.The proposed numerical results are compared with the analytical solutions and the solutions obtained by the other numerical methods.
文摘The application of wavelets is explored to solve acoustic radiation and scattering problems. A new wavelet approach is presented for solving two-dimensional and axisymmetric acoustic problems. It is different from the previous methods in which Galerkin formulation or wavelet matrix transform approach is used. The boundary quantities are expended in terms of a basis of the periodic, orthogonal wavelets on the interval. Using wavelet transform leads a highly sparse matrix system. It can avoid an additional integration in Galerkin formulation, which may be very computationally expensive. The techniques of the singular integrals in two-dimensional and axisymmetric wavelet formulation are proposed. The new method can solve the boundary value problems with Dirichlet, Neumann and mixed conditions and treat axisymmetric bodies with arbitrary boundary conditions. It can be suitable for the solution at large wave numbers. A series of numerical examples are given. The comparisons of the results from new approach with those from boundary element method and analytical solutions demonstrate that the new techique has a fast convergence and high accuracy.
