A numerical method is put forward in this paper, using the boundary element method （BEM） to model 3D terrain effects on magnetotelluric （MT） surveys, Using vector integral theory and electromagnetic field boundary...A numerical method is put forward in this paper, using the boundary element method （BEM） to model 3D terrain effects on magnetotelluric （MT） surveys, Using vector integral theory and electromagnetic field boundary conditions, the boundary problem of two electromagnetic fields in the upper half space （air） and lower half space （earth medium） was transformed into two vector integral equations just related to the topography ： one magnetic equation for computing the magnetic field and the other electrical equation for computing the electrical field. The topography integral is decomposed into a series of integrals in a triangle element. For the integral in a triangle element, we suppose that the electromagnetic field in it is the stack of the electromagnetic field in the homogeneous earth and the topography response which is a constant; so the computation becomes simple, convenient and highly accurate. By decomposition and computation, each vector integral equation can be calculated by solving three linear equations that are related to the three Cartesian directions. The matrix of these linear equations is diagonally dominant and can be solved using the Symmetric Successive Over-Relaxation （SSOR） method. The apparent resistivity curve of MT on two 3D terrains calculated by BEM is shown in this paper.展开更多
Using the boundary element method, the numerical modeling problem of three-dimensional terrain effect on magnetotelluric (MT) field is solved. This modeling technique can be run on PC in the case of adopting special n...Using the boundary element method, the numerical modeling problem of three-dimensional terrain effect on magnetotelluric (MT) field is solved. This modeling technique can be run on PC in the case of adopting special net division. The result of modeling test for 2-D terrain by this modeling technique is basically coincident with that by 2-D modeling technique, but there is a great difference between the results of 3-D and 2-D modeling for 3-D terrain.展开更多
THE modeling of 2-D terrain effect on magnetotelluric(MT)has been solved using finite ele-ment method(FEM)and boundary element method(BEM).This note uses BEM tosolve the problem.The solution of H_x- and E_x-polarizati...THE modeling of 2-D terrain effect on magnetotelluric(MT)has been solved using finite ele-ment method(FEM)and boundary element method(BEM).This note uses BEM tosolve the problem.The solution of H_x- and E_x-polarization wave can be obtained by the samemethod.Thus,this note only discusses the solution of H_x-polarization wave.展开更多
The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality ...The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.展开更多
基金This paper is supported by the National Natural Science Foundation ofChina (No .40344002) .
文摘A numerical method is put forward in this paper, using the boundary element method （BEM） to model 3D terrain effects on magnetotelluric （MT） surveys, Using vector integral theory and electromagnetic field boundary conditions, the boundary problem of two electromagnetic fields in the upper half space （air） and lower half space （earth medium） was transformed into two vector integral equations just related to the topography ： one magnetic equation for computing the magnetic field and the other electrical equation for computing the electrical field. The topography integral is decomposed into a series of integrals in a triangle element. For the integral in a triangle element, we suppose that the electromagnetic field in it is the stack of the electromagnetic field in the homogeneous earth and the topography response which is a constant; so the computation becomes simple, convenient and highly accurate. By decomposition and computation, each vector integral equation can be calculated by solving three linear equations that are related to the three Cartesian directions. The matrix of these linear equations is diagonally dominant and can be solved using the Symmetric Successive Over-Relaxation （SSOR） method. The apparent resistivity curve of MT on two 3D terrains calculated by BEM is shown in this paper.
基金Project supported by the National Natural Science Foundation of China
文摘Using the boundary element method, the numerical modeling problem of three-dimensional terrain effect on magnetotelluric (MT) field is solved. This modeling technique can be run on PC in the case of adopting special net division. The result of modeling test for 2-D terrain by this modeling technique is basically coincident with that by 2-D modeling technique, but there is a great difference between the results of 3-D and 2-D modeling for 3-D terrain.
文摘THE modeling of 2-D terrain effect on magnetotelluric(MT)has been solved using finite ele-ment method(FEM)and boundary element method(BEM).This note uses BEM tosolve the problem.The solution of H_x- and E_x-polarization wave can be obtained by the samemethod.Thus,this note only discusses the solution of H_x-polarization wave.
基金Supported by NationalNatural Science FoundationCouncil of the People’s Republic of China (20490224)
文摘The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.
