【摘要】 【目的】揭示齿型迷宫流道灌水器物理堵塞的内在流动特性成因,同步优化提出高抗堵型齿型灌水器流道结构。【方法】基于CFD数值模拟技术中的Workbench数值计算平台,对5种不同齿型流道结构(含改进后流道结构)的灌水器进行水砂两相流数值模拟计算,分析了不同齿型结构水流流速、流道内湍动能、湍动能耗散率分布规律及物理颗粒运动轨迹等。【结果】提出了齿型流道结构优化改进方案,优化后的流道结构增加了灌水器内低速区域面积和低速区域湍动能值,区间湍动能范围同比最高提升了52%～200%,同时提高了物理颗粒的运移速率,减少了颗粒运移路程和滞留时间,提升了齿型迷宫灌水器的抗堵塞性能。【结论】齿型流道灌水器的抗堵塞性能与流道内低速区的流体速度及流道内湍动能大小分布密切相关,流速和湍动能较大的区域不易造成堵塞;湍动能最大值均出现在主流区,并且在齿尖迎水区达到最大;湍流动能耗散率分布与湍动能分布具有十分相似的规律,湍动能耗散最严重的区域分布在齿尖处,齿尖结构对灌水器的消能效果起关键性作用。更多还原

【Abstract】 【Objective】The aim of this paper is to clarify the causes of the internal flow characteristics of the physical clogging in dental labyrinth emitter, and put forward the optimum parameters of the emitter with high anti-clogging performance. 【Method】Based on Workbench platform in CFD software, the water-sand two-phase flow characteristics in internal flow field were computed for five different dental labyrinth emitters with different dental flow channel, and the differences of flow velocity, turbulent kinetic energy, turbulent dissipation rate and physical particle trajectory under different dental structures were analyzed.【Result】Based on numerical simulation analysis, an improved scheme of optimizing the structure of the dental labyrinth emitter was proposed, and the optimized dental structure increased the area of the low-speed region and the turbulent kinetic energy of the low-speed region in the flow passage, and the range of turbulent kinetic energy was increased by 52%～200%compared with the other four dental structures, and the optimized dental structure increased the particle transport velocity, and reduced the transport distance and retention time of the particle, which improved the anti-clogging performance of dental labyrinth emitter.【Conclusion】The anti-clogging performance of the dental labyrinth emitter is closely related to the fluid velocity in the low velocity zone in the flow channel and the turbulent kinetic energy in the flow passage. Areas with high flow rates and turbulent energy are less likely to be clogging. The maximum value of turbulent kinetic energy appears in the mainstream and reaches the maximum value at the waterfacing area in the flow passage. The turbulent dissipation rate has similar distribution rules with turbulent kinetic energy, and the region with the most turbulent kinetic energy dissipation is located at the tip of the teeth. The dental structure plays a key role in the energy dissipation effect.更多还原