文丘里管内空化效果影响因素研究

Study on Factors Affecting Cavitation Effect in Venturi Tube

以文丘里管空化发生器为对象,通过考虑水中空气析出与消解过程的时变性,建立了水气两相的动态空化模型。运用FLUENT软件对水气两相流流动问题进行三维数值模拟研究,获得了文丘里管喉口直径、进口压力以及串联文丘里管等对汽含率变化产生影响的规律。数值模拟结果与实验相对比表明,汽含率随进口压力增加而增加,但并非无限增加,存在极限值;随着喉径的增加,文丘里管的空化效果逐渐减弱;相同条件下,串联文丘里管的空化效果不如单个文丘里管的空化效果,即串联文丘里管不能实现两级空化。以上研究对文丘里管的工程应用具有重要意义。

The dynamic cavitation model of air-water two-phase flow was established according to the time variation of air precipitation and digestion process in water,which was used in FLUENT three-dimension numerical simulation to simulate the air-water two-phase flow,and the variation law of venturi tube throat diameter、inlet pressure and tandem venturi on vapor volume fraction were obtained.The results of numerical simulation and experiments show that the vapor volume fraction increases with pressure increasing,But not infinitely increasing,there are limits;As the throat diameter increases,the cavitation effect of the venturi tube gradually decreases;Under the same conditions,the cavitation effect of the tandem venturi is not as good as the cavitation effect of a single venturi,that is,the two-stage cavitation cannot be realized by the tandem venturi.The above research is of great significance to the engineering application of venturi tubes.