This paper systematically discussed the equations for two-phase transient flow and pressure wave and interfacial wave. The behaviour of basic equations was analyzed. The formulas for the wave speed of the pressure wav...This paper systematically discussed the equations for two-phase transient flow and pressure wave and interfacial wave. The behaviour of basic equations was analyzed. The formulas for the wave speed of the pressure wave and the interfacial wave were derived. It was proved that various mathematical models can be uniformed by the integrating model and various wave speed formulas can be uniformed by the universal formula derived. The basic equations for the separated flow model are ill-conditioned because of the unreasonable neglect of the pressure differences between the phases and interfaces. Drift flux model can improve the accuracy if some additional equations are provided. The basic equations for homogeneous flow model are well-conditioned and they can be used in two-phase transient flow, especially in the cases of no velocity slips between various phases fluid.展开更多
A quasi two-dimensional two-phase flow cylinder model of slug motion in a voided line developed in this paper can predict reasonably the change of flow pattern of the slug, air entrainment, holdup and the distribution...A quasi two-dimensional two-phase flow cylinder model of slug motion in a voided line developed in this paper can predict reasonably the change of flow pattern of the slug, air entrainment, holdup and the distribution of axial velocity. However, if using the theory of transfer momentum to estimate the pressure-time history of slug at the elbow, the result of calculation is not good in agreement with that of experiment. Analysis of the experiment results and the estimations of using the theory of transient two-phase flow indicate that an evident water hammer response occurs in the slug, when the high-speed slug impacts on the elbow, and the peaks and waveform of pressure-time history are dependent mainly on the propagation of transient two-phase flow in the slug.展开更多
基金The Project was suppotted by Chinese National Natural Science Foundation.
文摘This paper systematically discussed the equations for two-phase transient flow and pressure wave and interfacial wave. The behaviour of basic equations was analyzed. The formulas for the wave speed of the pressure wave and the interfacial wave were derived. It was proved that various mathematical models can be uniformed by the integrating model and various wave speed formulas can be uniformed by the universal formula derived. The basic equations for the separated flow model are ill-conditioned because of the unreasonable neglect of the pressure differences between the phases and interfaces. Drift flux model can improve the accuracy if some additional equations are provided. The basic equations for homogeneous flow model are well-conditioned and they can be used in two-phase transient flow, especially in the cases of no velocity slips between various phases fluid.
文摘A quasi two-dimensional two-phase flow cylinder model of slug motion in a voided line developed in this paper can predict reasonably the change of flow pattern of the slug, air entrainment, holdup and the distribution of axial velocity. However, if using the theory of transfer momentum to estimate the pressure-time history of slug at the elbow, the result of calculation is not good in agreement with that of experiment. Analysis of the experiment results and the estimations of using the theory of transient two-phase flow indicate that an evident water hammer response occurs in the slug, when the high-speed slug impacts on the elbow, and the peaks and waveform of pressure-time history are dependent mainly on the propagation of transient two-phase flow in the slug.
