边坡高扬程虹吸排水管流态特征研究

研究目的：从实验及理论角度闸述边坡高扬程虹吸排水容易断流造成虹吸中断的原凶，并提供解决方案，实观虹吸排水的长期有效。创新要点研究方法重要结论：利用物理模型实验，结合理论解析推导，得到了高扬程虹吸排水管顶部流态特抓及其与管径的关系，解决了高扬程虹吸排水容易断流造成虹吸中断问题，保证了虹吸排水技术住边坡治理工程中的长期有效性。通过物理模型试验，揭示虹吸水流经过管顶区段的兰利，流型特征（见图4）；利用热力学理论推导，得到了虹吸水流绛过管顶区段由贴壁流向弹状流转变的临界管住，址公式（23）。管中形成气液共吲移动的完整掸状流是灾脱虹吸排水长期稳定的关键，虹吸水流绛过管硕区段由贴壁流向弹状流转变时存扯临界管仵。保讹边坡工群中虹吸排水长期稳定的管径以3．6mm为宜。

An investigation of flow characteristics in slope siphon drains

This paper presents a study of flow characteristics in high-lift siphon drains. A laboratory test was conducted to investigate the effects of hose diameter and flow velocity on siphon drainage. Three types of water flow were observed and analyzed. The experimental results show that the flow characteristics of siphon drainage are significantly influenced by the hose diameter. Water flows in the form of a wall pressing flow in a large diameter siphon hose (e.g., larger than 5.0 mm) under low flow velocity, which leads to discontinuous siphon drainage. However, water flows in the form of an integral slug flow in a small diameter siphon hose (e.g., smaller than 4.0 mm) under low flow velocity, which leads to continuous siphon drainage. Based on experimental observations, a thermodynamic derivation of the threshold of siphon hose diameter for continuous siphon drainage was analytically conducted. In slope engineering, a 3.6 mm polyurethane (PU) hose is recommended for siphon drainage.