In this paper, an investigation into the propagation of far field explosion waves in water and their effects on nearby structures are carried out. For the far field structure, the motion of the fluid surrounding the s...In this paper, an investigation into the propagation of far field explosion waves in water and their effects on nearby structures are carried out. For the far field structure, the motion of the fluid surrounding the structure may be assumed small, allowing linearization of the governing fluid equations. A complete analysis of the problem must involve simultaneous solution of the dynamic response of the structure and the propagation of explosion wave in the surrounding fluid. In this study, a dynamic adaptive finite element procedure is proposed. Its application to the solution of a 2D fluid-structure interaction is investigated in the time domain. The research includes：a） calculation of the far-field scatter wave due to underwater explosion including solution of the time-depended acoustic wave equation, b） fluid-structure interaction analysis using coupled Euler-Lagrangian approach, and c） adaptive finite element procedures employing error estimates, and re-meshing. The temporal mesh adaptation is achieved by local regeneration of the grid using a time-dependent error indicator based on curvature of pressure function. As a result, the overall response is better predicted by a moving mesh than an equivalent uniform mesh. In addition, the cost of computation for large problems is reduced while the accuracy is improved.展开更多
The main purpose of the present paper is to study almost paracomplex structures Euler-Lagrangian Equations on Walker 4-manifold with Walker metric. In this study, routes of bodies moving in space will be modeled mathe...The main purpose of the present paper is to study almost paracomplex structures Euler-Lagrangian Equations on Walker 4-manifold with Walker metric. In this study, routes of bodies moving in space will be modeled mathematically Euler-Lagrangian Equations on Walker 4-manifold with Walker metric that these are time-dependent partial differential equations. Here, we present paracomplex analogues of Euler-Lagrangian Equations on Walker 4-manifold with Walker metric. In addition, the geometrical-physical results related to paracomplex mechanical systems are discussed for Euler-Lagrangian Equations on Walker 4-manifold with Walker metric for dynamical systems. Finally, solution of the motion equations obtained as a result the study of using symbolic computational program is made.展开更多
文摘In this paper, an investigation into the propagation of far field explosion waves in water and their effects on nearby structures are carried out. For the far field structure, the motion of the fluid surrounding the structure may be assumed small, allowing linearization of the governing fluid equations. A complete analysis of the problem must involve simultaneous solution of the dynamic response of the structure and the propagation of explosion wave in the surrounding fluid. In this study, a dynamic adaptive finite element procedure is proposed. Its application to the solution of a 2D fluid-structure interaction is investigated in the time domain. The research includes：a） calculation of the far-field scatter wave due to underwater explosion including solution of the time-depended acoustic wave equation, b） fluid-structure interaction analysis using coupled Euler-Lagrangian approach, and c） adaptive finite element procedures employing error estimates, and re-meshing. The temporal mesh adaptation is achieved by local regeneration of the grid using a time-dependent error indicator based on curvature of pressure function. As a result, the overall response is better predicted by a moving mesh than an equivalent uniform mesh. In addition, the cost of computation for large problems is reduced while the accuracy is improved.
文摘The main purpose of the present paper is to study almost paracomplex structures Euler-Lagrangian Equations on Walker 4-manifold with Walker metric. In this study, routes of bodies moving in space will be modeled mathematically Euler-Lagrangian Equations on Walker 4-manifold with Walker metric that these are time-dependent partial differential equations. Here, we present paracomplex analogues of Euler-Lagrangian Equations on Walker 4-manifold with Walker metric. In addition, the geometrical-physical results related to paracomplex mechanical systems are discussed for Euler-Lagrangian Equations on Walker 4-manifold with Walker metric for dynamical systems. Finally, solution of the motion equations obtained as a result the study of using symbolic computational program is made.
