旋转水流消能及其空化特性

Energy Dissipation of Rotational Flow and Its Cavitation Characteristics

研究了高水头（Ｈ＞２００ｍ）泄水建筑物隧洞内部消能的一种新型消能工，将竖井与隧洞切向连接，在隧洞内形式螺旋形的旋转水流，这种水流结构可消散水流中大部分能量，使流向下游的水流剩余能量较小，减轻下游的消能负担和减少下游冲刷．这种消能工的最基本的水流形态环流，在其固体边壁存在着较大的离心力，其中心为大气压，整个水流不会出现负压，流速迅速降低，空化特性较好，不会产生空化与空蚀．还分析了旋转水流的消能机理、消能率、过水流量及流量系数．

This paper presents a new type of inner dissipaters in discharge tunnels of hydraulic structures,in which a screw rotational flow is formed by its tangential connection with the shaft of the glory hole spillway.This flow structure may disspate a great part of energy in flow,and thus the remaining downstream energy is small,as a result,the downstream load of dissipation of energy is reduced and the downstream scour of river bed decreased.The most elemental flow pattern ring flow in the dissipater is studied.At the rigid wall exist larger centrifugal forces and in the center core exists the atmospheric pressure;in the whole flow no negative pressure appears.The velocities decrease very fast and cavitation characteristics are good ,the cavitation and erosion do not occur.The mechanism of energy dissipution in the rotating flow,the rate of energy dissipation,the rate of discharge and coefficient of rate of discharge are also studied.