海底悬跨管道涡激振动问题十分复杂,需考虑流-管-土多场耦合效应。本文将悬跨管线简化为Euler-Bernoulli梁,两端跨肩管-土作用与线弹性弹簧和扭转弹簧近似,采用Van der pol方程描述旋涡脱落的尾迹特性。利用模态正交性对流-耦合控制方...海底悬跨管道涡激振动问题十分复杂,需考虑流-管-土多场耦合效应。本文将悬跨管线简化为Euler-Bernoulli梁,两端跨肩管-土作用与线弹性弹簧和扭转弹簧近似,采用Van der pol方程描述旋涡脱落的尾迹特性。利用模态正交性对流-耦合控制方程进行解耦,采用龙格-库塔法进行数值求解,重点分析非对称边界对海底管道涡激振动特性的影响。计算结果表明:非对称边界条件对最大响应幅值影响不大;约束条件越强烈,模态激发越难,响应频率越高。展开更多
With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results sho...With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.展开更多
The peristaltic transport of viscous fluid in an asymmetric channel is concentrated. The channel walls exhibit convective boundary conditions. Both cases of hydrodynamic and magnetohydrodynamic(MHD) fluids are conside...The peristaltic transport of viscous fluid in an asymmetric channel is concentrated. The channel walls exhibit convective boundary conditions. Both cases of hydrodynamic and magnetohydrodynamic(MHD) fluids are considered. Mathematical analysis has been presented in a wave frame of reference. The resulting problems are non-dimensionalized. Long wavelength and low Reynolds number approximations are employed. Joule heating effect on the thermal equation is retained. Analytic solutions for stream function and temperature are constructed. Numerical integration is carried out for pressure rise per wavelength. Effects of influential flow parameters have been pointed out through graphs.展开更多
In this paper,we extend Su-Zhang’s Cheeger-Mller type theorem for symmetric bilinear torsions to manifolds with boundary in the case that the Riemannian metric and the non-degenerate symmetric bilinear form are of pr...In this paper,we extend Su-Zhang’s Cheeger-Mller type theorem for symmetric bilinear torsions to manifolds with boundary in the case that the Riemannian metric and the non-degenerate symmetric bilinear form are of product structure near the boundary.Our result also extends Brning-Ma’s Cheeger-Mller type theorem for Ray-Singer metric on manifolds with boundary to symmetric bilinear torsions in product case.We also compare it with the Ray-Singer analytic torsion on manifolds with boundary.展开更多
Based on the theory of the complex variable functions, the analysis of non-axisymmetric thermal stresses in a finite matrix containing a circular inclusion with functionally graded interphase is presented by means of ...Based on the theory of the complex variable functions, the analysis of non-axisymmetric thermal stresses in a finite matrix containing a circular inclusion with functionally graded interphase is presented by means of the least square boundary collocation technique. The distribution of thermal stress for the functionally graded interphase layer with arbitrary radial material parameters is derived by using the method of piece-wise homogeneous layers when the finite matrix is subjected to uniform heat flow. The effects of matrix size, interphase thickness and compositional gradient on the interfacial thermal stress are discussed in detail. Numerical results show that the magnitude and distribution of interfacial thermal stress in the inclusion and matrix can be designed properly by controlling these parameters.展开更多
文摘海底悬跨管道涡激振动问题十分复杂,需考虑流-管-土多场耦合效应。本文将悬跨管线简化为Euler-Bernoulli梁,两端跨肩管-土作用与线弹性弹簧和扭转弹簧近似,采用Van der pol方程描述旋涡脱落的尾迹特性。利用模态正交性对流-耦合控制方程进行解耦,采用龙格-库塔法进行数值求解,重点分析非对称边界对海底管道涡激振动特性的影响。计算结果表明:非对称边界条件对最大响应幅值影响不大;约束条件越强烈,模态激发越难,响应频率越高。
基金Supported by the Science and Technology Program of the Education Department of Shaanxi Provincial Government(09JK378)the Key Scientific Research Fund of Shaanxi University of Technology(SLGKY12-02)~~
文摘With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.
基金support from Higher Education Commission (HEC) of Pakistan through Ph.D Indigeous Scheme.
文摘The peristaltic transport of viscous fluid in an asymmetric channel is concentrated. The channel walls exhibit convective boundary conditions. Both cases of hydrodynamic and magnetohydrodynamic(MHD) fluids are considered. Mathematical analysis has been presented in a wave frame of reference. The resulting problems are non-dimensionalized. Long wavelength and low Reynolds number approximations are employed. Joule heating effect on the thermal equation is retained. Analytic solutions for stream function and temperature are constructed. Numerical integration is carried out for pressure rise per wavelength. Effects of influential flow parameters have been pointed out through graphs.
基金supported by National Natural Science Foundation of China(Grant No.11101219)
文摘In this paper,we extend Su-Zhang’s Cheeger-Mller type theorem for symmetric bilinear torsions to manifolds with boundary in the case that the Riemannian metric and the non-degenerate symmetric bilinear form are of product structure near the boundary.Our result also extends Brning-Ma’s Cheeger-Mller type theorem for Ray-Singer metric on manifolds with boundary to symmetric bilinear torsions in product case.We also compare it with the Ray-Singer analytic torsion on manifolds with boundary.
基金supported by the National Natural Science Foundation of China(Grant No.11232007)the Funding for Outstanding Doctoral Dissertation in Nanjing University of Aeronautics and Astronautics(Grant No.BCXJ11-03)Funding of Jiangsu Innovation Program for Graduate Education(Grant No.CXZZ11_0191)
文摘Based on the theory of the complex variable functions, the analysis of non-axisymmetric thermal stresses in a finite matrix containing a circular inclusion with functionally graded interphase is presented by means of the least square boundary collocation technique. The distribution of thermal stress for the functionally graded interphase layer with arbitrary radial material parameters is derived by using the method of piece-wise homogeneous layers when the finite matrix is subjected to uniform heat flow. The effects of matrix size, interphase thickness and compositional gradient on the interfacial thermal stress are discussed in detail. Numerical results show that the magnitude and distribution of interfacial thermal stress in the inclusion and matrix can be designed properly by controlling these parameters.
