摇摆参数对自然循环下波谷型脉动的影响

针对摇摆条件下自然循环波谷型脉动进行研究,构建了计算波谷型脉动的模型并进行了分析,计算结果和实验值符合较好。分析结果表明:对于摇摆运动下的波谷型脉动,在其整体流动波动过程中起主导作用的是摇摆运动引起的附加压降,而在波谷附近,由于产汽的影响,局部摩擦压降和重位压降交替主导流动,并最终诱发波谷处的流动不稳定性;摇摆振幅和频率越大,即摇摆程度越剧烈时,摇摆附加压降波动越剧烈,流量、壁温等热工参数变化越剧烈,波谷型脉动起始点对应功率也越低。

Influence of Rolling Parameter on Trough Fluctuation in Natural Circulation

The influence of rolling parameters on trough fluctuation in natural circulation was researched. The mathematical model was developed to simulate trough fluctuation and the calculated results fit well with the experimental results. The calculated results indicate that for trough fluctuation under rolling motion, the additional force caused by rolling motion plays a main role in the whole flow fluctuation process, while near the trough, the local friction pressure drop and driving force caused by gravity dominate the flow alternately, which eventually induces instability near the trough. The bigger the amplitude and frequency of rolling motion are, namely the more intense the rolling motion is, the bigger the fluctuation of driving force caused by rolling is, thus causing larger fluctuation of flow rate and wall temperature, thereby the power corresponding to the starting point of trough instability is lower.