A non-linear dynamic model of one type of high-speed rotor system with gassupporting system is set up. The laws between the capacity force and the parameters of bearing, thestatic equilibrium position and rotating spe...A non-linear dynamic model of one type of high-speed rotor system with gassupporting system is set up. The laws between the capacity force and the parameters of bearing, thestatic equilibrium position and rotating speed are studied on the basis of above model. Then, thefailure rotating, speed is given in the working state, and the relation between the minimum failurerotating speed and clearance of bearing is also studied. At last, the stability and failurecondition are discussed in different working conditions.展开更多
In a two-phase flow, the vortex merging influences both the flow evolution and the particle motion. With the blobs-splitting-and-merging scheme, the vortex merging is calculated by a corrected core spreading vortex me...In a two-phase flow, the vortex merging influences both the flow evolution and the particle motion. With the blobs-splitting-and-merging scheme, the vortex merging is calculated by a corrected core spreading vortex method （CCSVM）. The particle motion in the vortex merging process is calculated according to the particle kinetic model. The results indicate that the particle traces are spiral lines with the same rotation direction as the spinning vortex. The center of the particle group is in agreement with that of the merged vortex. The merging time is determined by the circulation and the initial ratio of the vortex radius and the vortex center distance. Under a certain initial condition, a stretched particle trail is generated, which is determined by the viscosity, the relative position between the particles and the vortex, and the asymmetrical circulation of the two merging vortices.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50475112).
文摘A non-linear dynamic model of one type of high-speed rotor system with gassupporting system is set up. The laws between the capacity force and the parameters of bearing, thestatic equilibrium position and rotating speed are studied on the basis of above model. Then, thefailure rotating, speed is given in the working state, and the relation between the minimum failurerotating speed and clearance of bearing is also studied. At last, the stability and failurecondition are discussed in different working conditions.
基金Project supported by the National Natural Science Foundation of China (No. 10572020)
文摘In a two-phase flow, the vortex merging influences both the flow evolution and the particle motion. With the blobs-splitting-and-merging scheme, the vortex merging is calculated by a corrected core spreading vortex method （CCSVM）. The particle motion in the vortex merging process is calculated according to the particle kinetic model. The results indicate that the particle traces are spiral lines with the same rotation direction as the spinning vortex. The center of the particle group is in agreement with that of the merged vortex. The merging time is determined by the circulation and the initial ratio of the vortex radius and the vortex center distance. Under a certain initial condition, a stretched particle trail is generated, which is determined by the viscosity, the relative position between the particles and the vortex, and the asymmetrical circulation of the two merging vortices.
文摘自钻式原位剪切旁压试验(self-boring in-situ shear pressure-meter)以其独特的多级加载方式,能够直接测出土体的强度和变形参数,然而,目前对探头周围土体变形机理研究较少.为揭示自钻式原位剪切旁压仪试验过程中测定器周围土颗粒变形机理,应用PFC3D(particle flow code in three dimensions)颗粒流程序对自钻式原位剪切旁压试验进行了仿真数值模拟,对多级加载过程中探头周围土体的位移场和应力场发展变化以及数值试样各阶段变形模量和土颗粒运动轨迹进行了分析研究.试验结果表明:随着剪应力的逐级施加,中间区域颗粒的位移量不断增大,且位移矢量方向性更加显著.径向应力在探头附近两侧形成近似呈对称分布的数个"应力核";竖向应力在探头两侧形成扁平状应力带,且在肩部形成应力集中区.中部区域球颗粒的运动轨迹成台阶状,且随距探头距离的增大由近到远可分为3个特征区域;球颗粒的Z向和XY向位移量亦随之呈负指数形式衰减,Z向位移量衰减速率更快.
基金Supported by National Natural Science Foundation of China(51309123)Jiangsu Province Natural Science Research Projects in Colleges and Universities(13KJB570002)‘Qing Lan Project’of Colleges and Universities in Jiangsu Province,Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
