In order to visualize the 3-D field of explosion and describe the complex physical phenomena of explosion, the 3-D data resulting from numerical simulation by 3-D multi-material in cell (MMIC), and the application of ...In order to visualize the 3-D field of explosion and describe the complex physical phenomena of explosion, the 3-D data resulting from numerical simulation by 3-D multi-material in cell (MMIC), and the application of volume visualization is explored, based on the characteristics of explosion and shock. Based on this, a visualization system for 3-D explosion--ViSC3D is designed. Approaches for the visualization of 3-D field of explosion are presented. The algorithm and the functions of ViSC3D are also presented. ViSC3D is thus a useful tool to observe and analyze either the full picture or the details of a 3-D field of explosion, that are difficult to observe and analyze directly. With ViSC3D, the field of explosion between the hill slopes is visualized. The cutaway views and 2-D slices are also given. The full picture and partial details of 3-D field of explosion can be observed clearly. Furthermore, ViSC3D can be used to visualize other similar 3-D data fields.展开更多
In this paper a 3D numerical model was developed to study the complicated interaction between waves and a set of tandem fixed cylinders.The fluid was considered to be inviscid and irrotational.Therefore,the Helmholtz ...In this paper a 3D numerical model was developed to study the complicated interaction between waves and a set of tandem fixed cylinders.The fluid was considered to be inviscid and irrotational.Therefore,the Helmholtz equation was used as a governing equation.The boundary element method（BEM） was adopted to discretize the relevant equations.Open boundaries were used in far fields of the study domain.Linear waves were generated and propagated towards tandem fixed cylinders to estimate the forces applied on them.Special attention was paid to consideration of the effect on varying non-dimensional cylinder radius and distance between cylinders,ka and kd on forces and trapped modes.The middle cylinder wave forces and trapped modes in a set of nine tandem cylinders were validated utilizing analytical data.The comparisons confirm the accuracy of the model.The results of the inline wave force estimation on n tandem cylinders show that the critical cylinder in the row is the middle one for odd numbers of cylinders.Furthermore the results show that the critical trapped mode effect occurs for normalized cylinder radiuses close to 0.5 and 1.0.Finally the force estimation for n tandem cylinders confirms that force amplitude of the middle cylinder versus normalized separation distance fluctuates about that of a single cylinder.展开更多
Traditional methods for assessing effective roof support can be difficult to apply to complex three-dimensional excavations. Through worked examples,the approach of combined two-dimensional and three-dimensional numer...Traditional methods for assessing effective roof support can be difficult to apply to complex three-dimensional excavations. Through worked examples,the approach of combined two-dimensional and three-dimensional numerical modeling has been shown to be successful in understanding mechanisms of rock failure for unique excavation geometries and geotechnical properties and,in turn,provides adequate roof support recommendations for complex three-dimensional excavations in Australian coal mines. An interactive approach of monitoring and model review during the excavation process is an important part of model support recommendations to ensure rock failure and deformation in the model are representative of actual conditions,to provide effective and practical controls.展开更多
文摘In order to visualize the 3-D field of explosion and describe the complex physical phenomena of explosion, the 3-D data resulting from numerical simulation by 3-D multi-material in cell (MMIC), and the application of volume visualization is explored, based on the characteristics of explosion and shock. Based on this, a visualization system for 3-D explosion--ViSC3D is designed. Approaches for the visualization of 3-D field of explosion are presented. The algorithm and the functions of ViSC3D are also presented. ViSC3D is thus a useful tool to observe and analyze either the full picture or the details of a 3-D field of explosion, that are difficult to observe and analyze directly. With ViSC3D, the field of explosion between the hill slopes is visualized. The cutaway views and 2-D slices are also given. The full picture and partial details of 3-D field of explosion can be observed clearly. Furthermore, ViSC3D can be used to visualize other similar 3-D data fields.
文摘In this paper a 3D numerical model was developed to study the complicated interaction between waves and a set of tandem fixed cylinders.The fluid was considered to be inviscid and irrotational.Therefore,the Helmholtz equation was used as a governing equation.The boundary element method（BEM） was adopted to discretize the relevant equations.Open boundaries were used in far fields of the study domain.Linear waves were generated and propagated towards tandem fixed cylinders to estimate the forces applied on them.Special attention was paid to consideration of the effect on varying non-dimensional cylinder radius and distance between cylinders,ka and kd on forces and trapped modes.The middle cylinder wave forces and trapped modes in a set of nine tandem cylinders were validated utilizing analytical data.The comparisons confirm the accuracy of the model.The results of the inline wave force estimation on n tandem cylinders show that the critical cylinder in the row is the middle one for odd numbers of cylinders.Furthermore the results show that the critical trapped mode effect occurs for normalized cylinder radiuses close to 0.5 and 1.0.Finally the force estimation for n tandem cylinders confirms that force amplitude of the middle cylinder versus normalized separation distance fluctuates about that of a single cylinder.
文摘Traditional methods for assessing effective roof support can be difficult to apply to complex three-dimensional excavations. Through worked examples,the approach of combined two-dimensional and three-dimensional numerical modeling has been shown to be successful in understanding mechanisms of rock failure for unique excavation geometries and geotechnical properties and,in turn,provides adequate roof support recommendations for complex three-dimensional excavations in Australian coal mines. An interactive approach of monitoring and model review during the excavation process is an important part of model support recommendations to ensure rock failure and deformation in the model are representative of actual conditions,to provide effective and practical controls.
