格子气模型在地铁站人群疏散运动中的应用

基于格子气模型思想,引入高程因素,建立了模拟地铁站人员疏散的扩展非均匀格子气模型.该模型考虑紧急情况下人员的移动特征,引入多格子方法,根据人员实时步长确定人员移动速度.文中考虑了人员初始分布对疏散过程的影响,同时分析了紧急疏散出口对疏散的作用.利用该模型模拟了人有出口偏好的人员疏散过程和火灾情况下人员疏散过程,算例结果表明,适度地使用紧急疏散出口能提高疏散效率,高程因素的引入也促进了疏散进程.     

Wave Number Method for Three-Dimensional Steady-State Acoustic Problems

Based on the indirect Trefftz approach, a wave number method (WNM) is proposed to deal with three-dimensional steady-state acoustic problems. In the WNM, the dynamic pressure response variable is approximated by a set of wave functions, which exactly satisfy the Helmholtz equation. The set of wave functions comprise the exact solutions of the homogeneous part of the governing equations and some particular solution functions. The unknown coefficients of the wave functions can be obtained by enforcing the pressure approximation to satisfy the boundary conditions. Compared with the boundary element method (BEM), the WNM have a smaller system matrix, and is applicable to the radiation problems since the wave functions are independent of the domain size. A 3D acoustic cavity is exemplified to show the properties of the method. The results show that the wave number method is more efficient than the BEM, and it is fairly accurate.     

基于粒子群算法(PSO)的人员疏散动力学模型

基于粒子群算法思想,建立紧急情况下公共场馆人员疏散的动力学模型.该模型考虑人员之间的相互作用,依据人员实时局部密度的变化改变个体的最大速度以及保有区域尺寸,具有时空非均匀的特点.定义个体冲量以及受伤冲量阈值,考虑人员受伤对疏散过程的影响,同时还比较了多出口疏散与单出口疏散的特点和效率.算例结果表明,疏散结果与元胞自动机模型相似,理想化更新流程的结果小于其他疏散模型的结果.