The occurrence of underground piping is a pluralistic and complex problem. Due to the great difficulty of the 3D dynamic simulation of piping both by theoretical and numerical analysis, currently there is no satisfact...
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ISBN:
(纸本)9783037853474;9783038137900
The occurrence of underground piping is a pluralistic and complex problem. Due to the great difficulty of the 3D dynamic simulation of piping both by theoretical and numerical analysis, currently there is no satisfactory mathematical model and numerical analysis software for it. In order to simulate the piping development process of sluice or dike foundation, in this paper, the 3D steady-unsteady saturated-unsaturated FEM seepage simulation method is used, and the concepts of destroyed element and variable grid method are introduced. The destroyed elements are removed from the original grid during the iterative calculation process, and the corresponding procedure for the 3D steady-unsteady piping process of sluice foundation is designed. Using appropriate post-processing program, the whole piping development of a sluice foundation can be displayed. A piping test of a sluice foundation model is simulated by the method provided in this paper. For the comparison of the experimental result and the simulation result, they showed very good agreement, which can verify the correctness of the piping simulation and programming methods given in this paper.
This study proposes an elastic finite difference(FD)time domain method with variablegrids in three-dimensional cylindrical *** calculations will diverge and become less accurate by conventional cylindrical FD as the ...
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This study proposes an elastic finite difference(FD)time domain method with variablegrids in three-dimensional cylindrical *** calculations will diverge and become less accurate by conventional cylindrical FD as the grid size gradually becomes more extensive with the increasing *** prevent grids from being too coarse in far fields,we compensate for the grid cell infl ation by refi ning the grid step in the azimuthal *** variablegrid FD in the cylindrical coordinate systems has a higher effi ciency in solving acoustic logging while drilling(LWD)problems because the grid boundaries are consistent with those of the drill collar and the *** proposed algorithm saves approximately 94%of the FD grids,80%of the computation time,and memory with a higher calculation accuracy than the FD on rectangular grids for the same *** also calculate the acoustic LWD responses of the fl uid-fi lled borehole intersecting with *** ections are generated at the fractures,which can be equivalent to an additional scattering *** mode conversions between the collar and the Stoneley waves are *** Stoneley spectra are more sensitive to the ***,the logs in a heterogeneous formation with two refl ectors far from the borehole are modeled,and a means of estimating the azimuth of geological interfaces from refl ections is proposed.
In this paper we study numerical computations of oxygen diffusion problems with a moving oxidation front on unbounded domains of planar, cylindrical and spherical geometrical shapes. A new domain transformation techni...
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In this paper we study numerical computations of oxygen diffusion problems with a moving oxidation front on unbounded domains of planar, cylindrical and spherical geometrical shapes. A new domain transformation technique of space variables and time variable is introduced in the application of the variable grid method for numerical computation of these problems. Some upper bound estimates of oxidation fronts are obtained. A numerical algorithm is proposed and discussed. (C) 1998 John Wiley & Sons, Ltd.
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