A good understanding of pedestrian movement in the transfer corridor is vital for the planning and design of the station,especially for efficiency and safety.A multi-force vector grid model was presented to simulate t...A good understanding of pedestrian movement in the transfer corridor is vital for the planning and design of the station,especially for efficiency and safety.A multi-force vector grid model was presented to simulate the movement of bidirectional pedestrian flow based on cellular automata and forces between pedestrians.The model improves rule-based characteristics of cellular automata,details forces between pedestrians and solves pedestrian collisions by a several-step updating method to simulate pedestrian movements.Two general scenarios in corridor were simulated.One is bidirectional pedestrian flow simulation with isolation facility,and the other is bidirectional pedestrian flow simulation without isolation facility,where there exists disturbance in the middle.Through simulation,some facts can be seen that pedestrians in the case with isolation facility have the largest speed and pedestrians in the case without isolation facility have the smallest speed; pedestrians in the case of unidirectional flow have the largest volume and pedestrians in the case of without isolation facility have the smallest volume.展开更多
The microscopic response characteristics of nuclear magnetic resonance(NMR) are widely used for characterizing complex pore structures of rocks. Due to the prohibitive NMR experiment cost, numerical simulation was emp...The microscopic response characteristics of nuclear magnetic resonance(NMR) are widely used for characterizing complex pore structures of rocks. Due to the prohibitive NMR experiment cost, numerical simulation was employed as an alternative approach to verify some theoretical aspects of NMR responses. Firstly, the basic principles of pore-scale NMR simulation based on random-walk method(RWM) were introduced. The RWM-simulated results were benchmarked with the analytical results for an ideal spherical pore model. Then, the effects of two numerical parameters, namely diffusion radius and walk numbers, were studied on the simulation accuracy. The simulation method is then applied to various pore models with different pore sizes and pore shapes filled with different fluids to study the microscopic NMR response characteristics. The numerical experiments are useful for understanding and interpreting NMR measurements and the simulation code provides a numerical tool to perform pixel-based digital rock analysis.展开更多
基金Project(51238008)supported by the National Natural Science Foundation of ChinaProject(CXZZ13_0116)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(YBJJ1344)supported by the Scientific Research Foundations of Graduate School of Southeast University,China
文摘A good understanding of pedestrian movement in the transfer corridor is vital for the planning and design of the station,especially for efficiency and safety.A multi-force vector grid model was presented to simulate the movement of bidirectional pedestrian flow based on cellular automata and forces between pedestrians.The model improves rule-based characteristics of cellular automata,details forces between pedestrians and solves pedestrian collisions by a several-step updating method to simulate pedestrian movements.Two general scenarios in corridor were simulated.One is bidirectional pedestrian flow simulation with isolation facility,and the other is bidirectional pedestrian flow simulation without isolation facility,where there exists disturbance in the middle.Through simulation,some facts can be seen that pedestrians in the case with isolation facility have the largest speed and pedestrians in the case without isolation facility have the smallest speed; pedestrians in the case of unidirectional flow have the largest volume and pedestrians in the case of without isolation facility have the smallest volume.
基金Project(265201248) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(41172130) supported by the National Natural Science Foundation of China+2 种基金Project(2011ZX05014-001) supported by the Major State S&T Special Fund,ChinaProject(201205002) supported by the China Scholarship CouncilProject(2011D-5006-0305) supported by the China National Petroleum Co.Innovation Foundation,China
文摘The microscopic response characteristics of nuclear magnetic resonance(NMR) are widely used for characterizing complex pore structures of rocks. Due to the prohibitive NMR experiment cost, numerical simulation was employed as an alternative approach to verify some theoretical aspects of NMR responses. Firstly, the basic principles of pore-scale NMR simulation based on random-walk method(RWM) were introduced. The RWM-simulated results were benchmarked with the analytical results for an ideal spherical pore model. Then, the effects of two numerical parameters, namely diffusion radius and walk numbers, were studied on the simulation accuracy. The simulation method is then applied to various pore models with different pore sizes and pore shapes filled with different fluids to study the microscopic NMR response characteristics. The numerical experiments are useful for understanding and interpreting NMR measurements and the simulation code provides a numerical tool to perform pixel-based digital rock analysis.
