平面旋涡(中心型奇点)水力特性的探讨

Discussion on hydraulic properties of plane vortex with standing center

本文讨论了平面旋涡（中心型奇点）的水力特性．说明了这种旋涡的中心被封闭的流线所包围，中心点的流速为零，封闭流线为椭圆曲线；给出了旋涡内流速与压强，旋涡的环量、涡量以及角动量的表达式；建立了旋涡水力参数和主流水力参数的连接条件，包括两个运动连接条件和两个动力连接条件；将得到的理论结果应用于侧墙突扩或跌坎流，得到的旋涡中心压强表明，在一般明渠条件下，主流流速大于２０ｍ／ｓ时旋涡区有可能出现空蚀；应用于水跃时发现，跃长与跃高之比和突扩流旋涡的长宽比基本相同，估计了水跃旋滚区的紊流运动粘滞系数；应用于交岔渠道的旋涡时，指出了旋涡宽度与渠宽之比必须小于０１６０，给出了一个数例．

This paper is concerned with the hydraulic properties of vortex which has a standing center and is enclosed by stream lines. The parameters such as velocity, pressure, vorticity, circulation and angular momentum are deduced. Furthermore, four connective conditions are discussion to connect the vortex to the main flow. The results are applied to some practical conditions such as post step flow, hydraulic jump and channel junction. Some of the conclusions are very useful.