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排序方式: 共有682条查询结果,搜索用时 15 毫秒
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为了在虚拟三维环境中模拟出森林火灾的发展蔓延状态,利用三维引擎进行仿真研究。说明了三维元胞的定义、状态、邻域和转换规则函数;通过求得林火蔓延公式的参数在在8个邻域方向上的分量,得到林火蔓延公式在相应方向上的分量公式。利用Unity3D三维引擎建立野外三维地形,通过不断调整其自带粒子系统的参数,建立适用于不同条件的火焰库和烟雾库,输入气象因素后即可实现林火在三维环境下的模拟蔓延。将野外实地点烧数据与模拟效果进行对比,可以看出模拟的效果与实地点烧相近,模拟效果符合要求。 相似文献
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A modified cellular automaton model is developed to depict the interface evolution inside the cementite plus ferrite lamellar microstructures during the reaustenitization of a pearlite steel. In this model, migrations of both the austenite–ferrite and austenite–cementite interfaces coupled with the carbon diffusion and redistribution are integrated. The capillarity effect derived from local interface curvatures is also carefully considered by involving the concentration given by the phase diagram modified by the Gibbs–Thomson effect. This allows the interface evolution from a transient state to a steady state under different annealing conditions and various interlamellar spacings to be simulated. The proposed cellular automaton approach could be readily used to describe the kinetics of austenite formation from the lamellar pearlites and virtually reveal the kinematics of the moving interfaces from the microstructural aspect. 相似文献
626.
Fluid flow has a significant impact on the microstructure evolution of alloys during solidification. Based on the previous work relating simulation of the dendritic growth of magnesium alloys with hcp (hexagonal close-packed) structure, an extension was made to the formerly established CA (cellular automaton) model with the purpose of studying the effect of fluid flow on the dendritic growth of magnesium alloys. The modified projection method was used to solve the transport equations of flow field. By coupling the flow field with the solute field, simulation results of equiaxed and columnar dendritic growth of magnesium alloys with fluid flow were achieved. The simulated results were quantitatively compared with those without fluid flow. Moreover, a comparison was also made between the present work and previous works conducted by others. It can be concluded that a deep understanding of the dendritic growth of magnesium alloys with fluid flow can be obtained by applying the present numerical model. 相似文献
627.
A multiphase cellular automaton model was developed to simulate microstructure evolution of near eutectic spheroidal graphite cast iron (SGI) during its solidification process, and both dendritic austenite and spheroidal graphite growth models were adopted. To deduce the mesh anisotropy of cellular automaton method, the composition averaging and geometrical parameter were introduced to simulate the spheroidal graphite growth. Solute balance method and decentered square algorithms were employed to simulate austenite dendrites growth with different crystallographic orientations. The simulated results indicate that the graphite nodule grows in a spherical morphology when the surrounding environment of a single graphite nodule is same. However, for two adjacent graphite nodules, the environment is different. The higher the carbon concentration, the faster the growth of graphite. By comparison with experimental results, it is found that the microstructure evolution of near eutectic spheroidal graphite cast iron during solidification process can be reproduced quantitatively by numerical simulation with this model. 相似文献
628.
基于入匝道系统的元胞自动机交通流模型,从安全距离的角度提出四种换道规则,探讨四种换道规则对匝道系统的影响。模拟计算结果表明,匝道上的不同换道行为对匝道交通流模型有重大影响。安全距离为零的换道行为,能使匝道路段的流量获得最大值,但是却会抑制主道上游路段和下游路段的车辆流量;同时考虑了与前后车有安全距离的换道行为,不仅能让主道上下游路段的流量达到最大值,还能使整个匝道系统的流量达到最大值。 相似文献
629.
彭家寅 《计算机工程与应用》2012,48(28):57-60
初步建立了具有某种分配律的扩展格序效应代数和格序QMV代数这两种unsharp量子结构上的自动机与文法理论的基本框架。引入了ε-值正则文法的概念,证明了任意ε-值自动机识别的语言等价于某种ε-值正则文法所生成的语言;反之,任意[ε]-值正则文法所生成的语言等价于某种ε-值自动机识别的语言。讨论了ε-值正则语言在和、连接及反转运算下的封闭性质。 相似文献
630.