油柱分離時における空気析出モデルの検討

抄録

In the pipeline of a hydraulic system or a liquid transportation system, liquid column separation occurs when the pressure drops below the gas release pressure or saturated vapor pressure. When the cavity produced by the column separation collapses, an extraordinary high build-up of pressure, which is very harmful for the hydraulic system and the components, can occur. The behavior of the dissolved air contained in the liquid makes this even more complicated. To predict the duration of the separation and the peak pressure caused by the collapse, a simple one-dimensional model is proposed, in which gas-liquid surfaces are taken and the effect of released air is taken into account using a homogeneous mixture approximation and the method of characteristics. With regards to the first pressure peak, the calculated results agree well with the experimental ones.