围压作用下自振空化射流脉动特性实验研究

就围压下自振空化射流动压力特性进行了实验研究，其实验结果表明：在围压作用下，自振空化射流脉动幅度存在最优喷距，并且最优喷距随围压的增大而增大；在压降一定情况下，脉动幅度随围压的增加而减小；在围压和压降一定时，自振空化射流的最大冲击压力明显高于普通连续射流；自振空化射流的脉动频率，基本不随围压、压降和喷距的变化而变化，在本实验条件下，基本保持在１．３８ＫＨｚ 左右

An Experimental Study on Self-Resonant Cavitating Jet under Ambient Pressure

Self resonant cavitating jet is a new kind of efficient water jet developed in recent years and has been widely used in many industries, especially in petroleum industry, due to its violent pressure oscillation. In drillling and production, self resonant cavitating jet can increase the penetration rate and remove impurities in near well bore formation to improve production. The dynamic pressure characteristics of self resonant cavitating jet under ambient pressure are still unknown, the distribution of jet dynamic pressure of self resonant cavitating jet without effect of ambient pressure has been reported in most studies. A study on pressure distribution of self resonant cavitating jet has been made under ambient pressure (0～10MPa). The results show that there is an evident effect of the ambient pressure on the jet pressure distribution and exists similar self preservation in self resonant cavitating jet with ambient pressure. The pressure at self resonant cavitating jet axis descents faster under ambient pressure. In self resonant cavitating jet,there is an optimum distance in the impulse amplitude of pressure, it increases as the ambient pressure increases. The impulse amplitude of pressure at self resonant cavitating jet axis becomes lower as the ambient pressure increases. The frequency of self resonant cavitating jet basically does not change as the ambient pressure varies. The impact pressure peak is obviously greater than that of the normal water jet.