【摘要】 虹吸式屋面雨水系统传统水力设计时一般通过控制系统最低负压来防止气蚀,根据气蚀理论,虹吸系统局部气蚀的形成与流速、压力、饱和蒸气压等各因素相关。引入气穴数的概念综合上述因素的影响作用,研究预测虹吸系统局部气蚀风险的方法;针对虹吸系统常用管材,分析材料机械性能,评判其气蚀抗力。更多还原

【Abstract】 The cavitation risk is generally prevented by limiting the negative pressure value of the system in the traditional hydraulic design of siphonic roof drainage systems.According to the theory of cavitation,the formation of local cavitation in the siphonic system is related to various factors,such as flow rate,pressure and vapor pressure.In this paper,the concept of cavitation index is introduced,the definition of which integrates the influence of these factors.And the method of predicting local cavitation risk of the siphonic system is studied.The mechanical properties of the pipe materials which usually used on siphonic systems are analyzed and the cavitation resistance of which is also evaluated.更多还原