窄矩形通道内 Ledinegg 不稳定性实验研究

摘要

为研究窄矩形通道Ledinegg不稳定性，分析影响系统Ledinegg不稳定性的主要因素，对窄矩形通道进行了一系列的实验研究和数学理论推导。实验表明：随热流密度的增加或系统压强的减小，窄矩形通道内部特征曲线负斜率区斜率变小。此斜率越小，系统发生不稳定的概率越大，且流量漂移的波动振幅越大；与常规通道不同，过冷度对窄矩形通道Ledinegg不稳定性的影响程度很小。在忽略窄矩形通道内的加速压降和重力压降，仅考虑摩擦压降的情况下，推导出窄矩形通道内部特征曲线的数学关系式，给出了系统达到稳定的数学条件。%In order to study the Ledinegg flow instability in rectangular narrow channel and analyze the main factors that impact the flow instability of the system ,a series of experimental studies and mathematical theoretical derivations were carried . The experimental results show that with the increase of heat flux or the decrease of system pressure , the slope of internal characteristic curve in the negative slope region decreases . T he smaller slope results in a bigger possibility of system instability , the bigger fluctuant amplitude of flow excursion .Different from conventional channel ,the impact of subcooling on Ledinegg flow instability in rectangular narrow channel is small .Considering only the frictional pressure drop , and ignoring the acceleration pressure drop and gravity pressure drop , a mathematical correlation of the internal characteristic curve in narrow channel was deduced and the mathematical conditions of a stable system were provided .