并联矩形通道流动不稳定性模型研究

Research on Model of Flow Instability in Parallel Rectangular Channels

针对并联矩形通道,基于积分法建立包括入口段、加热段和上升段的并联通道流动不稳定性模型,开发并联矩形通道流动不稳定性分析程序,并采用国内外并联通道流动不稳定性实验对程序进行验证;其次,采用计算分析程序分析并联矩形双通道系统压力、入口及出口节流等条件对矩形双通道流动不稳定性边界和系统脉动频率的影响。分析结果表明,不同压力下系统流动不稳定性边界和系统脉动频率分布重合,但对相同入口过冷度工况,随着压力增大,系统稳定性增强,系统脉动频率增大;随着入口阻力系数增加和出口阻力系数减小,系统稳定性增强,系统脉动频率增大。

A mathematical and physical model for flow instability in one dimensional parallel rectangular channels was established, including the entrance section, heater section and riser section, and the code for flow instability in parallel two-rectangular channel was developed based on the mathematical model, which was validated with the experimental results of flow instability. Based on the code, the effect of the system pressure, the inlet and outlet throttling on the margin of stability and the frequency of oscillations was analyzed. The results showed that the margin of stability and the distribution of frequency were overlapped at different system pressure and the system would be stabilized and the frequency of the system would increase with the increasing of the inlet throttling and system pressure and the decreasing of outlet throttling.