摘要：Surface vortex behavior in front of the tunnel intake was investigated in this *** critical submergence of vortex was discussed based on the concept of 'critical spherical sink surface'(CSSS).The vortex formation and evolution at the tunnel intake were analyzed based on the theory of CSSS considering the effect of circulation.A theory was proposed to explain the surface *** theoretical development was verified by the physical model experiments of Xiluodu hydropower *** radial velocity and vortex circulation were considered as the main factors that influence the formation and evolution of surface ***,an anti-vortex intake configuration was proposed to weaken the air-core vortex in front of the tunnel intakes of the hydraulic structures.

摘要：一些鸟类的脖颈具有出色的柔性弯曲能力,模仿其特性可以设计仿生机器人.该类仿生设计的主要挑战是如何处理鸟类脖颈固有的灵活性和冗余的自由度.本文以鸡的脖颈结构为例,提出了一种模仿其脖颈结构特征的仿生超冗余机器人的设计方法.在我们的设计中,首先研究鸡脖颈的多骨节连接与运动特性,并定义了一个具有弹簧和万向节组合的仿生椎骨单元(BVU)来模拟鸡脖颈结构.然后,由三根钢丝平行驱动的三个仿生椎骨单元形成单个颈椎节段.最后,连接四个相同的颈椎节段构成了所提出的仿生超冗余机器人.结合几何分析法和Denavit-Hartemberg(D-H)参数法,研究了仿生超冗余机器人的驱动空间、关节空间和任务空间的运动学关系.通过蒙特卡洛方法进一步计算了可达工作空间.此外,原型样机的单平面运动实验的最大位置偏差约为四个颈椎节段总长度的5.8%.同时,一系列空间形状的展示,包括S形仿生弯曲配置和对兴趣目标体的成功缠绕和提升,证明了所提出的设计方法的有效性、机器人具有优异的灵活性和应用潜力.