Abstract:

In order to investigate the two-phase frictional pressure drop characteristics of boiling flows in a rectangular narrow channel under rolling motion, a series of thermal hydraulic experiments and theoretical analysis are performed. The results demonstrate that the additional inertial force is imposed on the fluid and the space of experimental loop will vary periodically under rolling motion. The fluctuation amplitude of the two-phase frictional gradient increases with increasing rolling angle and rolling period. The fluctuation amplitude and time average value of the two-phase frictional pressure gradient increase with increasing heat flux, while it decreases with the increase of system pressure. The mass flux varies with the fluctuation of frictional pressure gradient at the same period. The phase change between the fluctuation of mass flux and frictional pressure gradient is approximately equal to 1/4 rolling period due to the velocity difference of the pressure propagation and mass flux increases.

Key words: rolling motion, rectangular narrow channel, phase change, two-phase flow, heat transfer

摘要：

为了研究摇摆工况下窄矩形通道内的两相摩擦压降特性,进行了一系列的热工水力实验和理论分析。结果表明,摇摆工况下流体会受到附加惯性力的作用且实验回路的空间位置也会出现周期性的变化,两相摩擦压降梯度的波动振幅随着摇摆角度和摇摆周期的增加而增加;随着通道热通量的增加或者系统压强的减小,两相摩擦压降梯度的波动振幅和时均值逐渐增加。窄矩形通道内的质量流速随着两相摩擦压降梯度的波动而波动,且具有相同的波动周期,由于流体加速和压力传播的速度不同,流量波动和摩擦压降波动存在约1/4周期的相位差。

关键词: 摇摆运动, 窄矩形通道, 相变, 两相流, 传热