One of the pressing problems in hydraulic engineering is that the solid boundary, in the form of a circular arc, is apt to produce cavitation and sustain damage under the action of high-velocity flow. As the reason of...One of the pressing problems in hydraulic engineering is that the solid boundary, in the form of a circular arc, is apt to produce cavitation and sustain damage under the action of high-velocity flow. As the reason of the occurrence of cavitation in the end region of a circular arc is yet unknown, we cannot predict the cavitation inception for a given solid boundary condition. Recently we have made some research work about this problem. The results are the following:展开更多
Ⅰ. INTRODUCTION Many shock waves in the interplanetary space are produced by burst processes. Therefore it is certain that the acceleration process accompanying these shock waves should have a time evolution effect. ...Ⅰ. INTRODUCTION Many shock waves in the interplanetary space are produced by burst processes. Therefore it is certain that the acceleration process accompanying these shock waves should have a time evolution effect. One of the time evolution effects is that the energy spectrum of accelerated particles varies with time. This is revealed by展开更多
The fundamental solution to dynamic elastic differential equation after the Laplace transformation, which was obtained by Cruse and Rizzo, has been utilized to solve the boundary integral equation formulated by the we...The fundamental solution to dynamic elastic differential equation after the Laplace transformation, which was obtained by Cruse and Rizzo, has been utilized to solve the boundary integral equation formulated by the weighted residual method. The boundary element method has been applied to dealing with the heavy tamping problem. As the elasticity modulus of soil is gradually increased after each tamping, and the loading modulus and unloading modulus are quite different, residual deformations can be finally obtained for each tamping. This is a method of nonlinear elastic analysis. The relationship of hammer velocity and falling distance for heavy tamping within liquid has been derived, so providing a theoretical background for heavy tamping under water.展开更多
文摘One of the pressing problems in hydraulic engineering is that the solid boundary, in the form of a circular arc, is apt to produce cavitation and sustain damage under the action of high-velocity flow. As the reason of the occurrence of cavitation in the end region of a circular arc is yet unknown, we cannot predict the cavitation inception for a given solid boundary condition. Recently we have made some research work about this problem. The results are the following:
文摘Ⅰ. INTRODUCTION Many shock waves in the interplanetary space are produced by burst processes. Therefore it is certain that the acceleration process accompanying these shock waves should have a time evolution effect. One of the time evolution effects is that the energy spectrum of accelerated particles varies with time. This is revealed by
文摘The fundamental solution to dynamic elastic differential equation after the Laplace transformation, which was obtained by Cruse and Rizzo, has been utilized to solve the boundary integral equation formulated by the weighted residual method. The boundary element method has been applied to dealing with the heavy tamping problem. As the elasticity modulus of soil is gradually increased after each tamping, and the loading modulus and unloading modulus are quite different, residual deformations can be finally obtained for each tamping. This is a method of nonlinear elastic analysis. The relationship of hammer velocity and falling distance for heavy tamping within liquid has been derived, so providing a theoretical background for heavy tamping under water.
