低温液体输送路流场空化裕度准则及试验介质影响研究

Study on the Criteria of Cavitation Margin of Flow Field in Cryogenic Fluid Feed Line and the Influence of Test Medium

针对低温液体输送路流场空化现象,分析了空化发展过程和机理,对比了空化初生准则和基于气蚀流量的出流口限流准则,研究试验介质对空化试验的影响,并进行了空化试验验证。结果表明,与空化初生准则相比,基于气蚀流量的低温液体出流口限流准则是一种更便捷、有效的空化裕度评估方法,适用性好、可测性强;出流口气蚀流量系数由出流结构形式及参数决定,介质、压力和温度工况对出流口气蚀流量系数影响较小,介质替代试验具有可行性。

This article focused on the cavitation phenomenon in the flow field of the conveying road,cavitation development process and mechanism analysis were carried out.The cavitation incipient criterion and the outflow restriction criterion based on the cavitation flow rate were compared.The influence of the test medium on the cavitation test were studied and verified by cavitation test.The results show that,compared with the cavitation incipient criterion,the outflow restriction criterion based on the cavitation flow rate is a more convenient and effective method for evaluating cavitation margin.This method has good applicability and strong testability.The cavitation flow coefficient of the outlet is determined by the structure and parameters of the outlet.Medium,pressure and temperature conditions have little effect on it,which means the medium substitution test is feasible.