虹吸式屋面雨水排水系统单斗虹吸启动数值模拟研究

Investigation and numerical modelling of the priming of single-outlet siphonic roof drainage system

虹吸式屋面雨水排水系统的虹吸启动流量、启动时间影响到雨水天沟容积的确定以及虹吸系统是否能顺利、有效运行。运用CFD计算流体力学方法,对DN56、DN75、DN90、DN110规格的虹吸雨水斗在天沟内的运行情况进行建模,模拟雨水流经不同规格雨水斗时的流态及进入管路系统后的虹吸启动情况,并对比分析已有水力试验数据,对差异存在的可能原因进行探讨。结果表明,CFD数值模拟结果与水力试验数据接近,因此CFD数值模拟方法可为相关产品和系统的研发提供辅助设计。

The capacity and time of priming of siphonic roof drainage system affect the determining of gutter capacity and whether or not the system could operate successfully and effectively. Applying the method of computational fluid dynamics(CFD),the DN56,DN75, DN90, DN110 siphonic roof outlets are modelled in the same gutter,through which the rainwater flow with its flow regime and priming process being numerical simulated. At the same time, by comparing with the existing hydraulic test data, the possible causes of the difference are to be discussed. The results indicate that the CFD numerical modelling data is close to the hydraulic test data, therefore, the method of CFD numerical modelling could provide some aided design for related products and systems.