中文摘要：

空腔环流内的气体压强与许多水动力学特性直接有关，是重要的水动力学的边界条件之一。在吸吮流流态下，当起旋器出口的水流傅汝德数较大时，空腔环流内负压的大小，主要与通气孔直径有关，但沿程的变化可视为常数；水平旋流洞起始断面的相对真空度与相对通气孔直径的关系为指数关系；下游水位对空腔内气体压强有明显的影响，在某一下游水位时空腔内的气体压强有最小值。根据气体压强、离心力压强和壁面压强之间的关系可知，离心力压强是造成壁面压强和壁面切应力沿程变化的主要因素；空腔环流内负压大小不同时，水平洞内水流能动量的转变规律是不同的。

英文摘要：

Air pressure of horizontal rotary flow in internal energy dissipation tunnel is correlated to a lot of hydraulic characteristics and is one of important boundary conditions. In the case of the absorbing flow pattern, the air pressure is mainly determined by the diameter of ventilation hole and may be considered as a constant along the level tunnel when Froude number of the rotary starter outlet is larger. The relation is an index one between the relative air pressure and the relative diameter of ventilation hole at the initial section of level tunnel. The air pressure is obviously influenced by the down water level and has a minimal value for some down water level. The centrifugal pressure is the main factor which determines the behaviors of the wall pressure and wall shearing stress according to an analysis. The law of energy transformation is different corresponded a larger or smaller amount of the air pressure.