齿型迷宫灌水器抗堵塞性能分析与结构优化模拟
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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。
【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.
【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.
引文
[1]牛文全,喻黎明,吴普特,等.迷宫流道转角对灌水器抗堵塞性能的影响[J].农业机械学报, 2009, 40(9):51-55.
[2]穆乃君,张昕,李光永,等.内镶片式齿型迷宫滴头抗堵塞试验研究[J].农业工程学报, 2007, 23(8):34-39.
[3]芦刚,史玉升,魏青松,等.基于两相流模拟的高抗堵滴灌灌水器开发方法[J].华中科技大学学报(自然科学版), 2007, 35(7):118-121.
[4]马晓鹏,龚时宏,王建东,等.额定压力及低压下内镶片式滴头抗堵塞性能试验[J].农业机械学报, 2011, 42(7):86-90.
[5]武鹏,牛文全,常莹华,等.齿形迷宫流道不同结构参数下灌水器抗堵塞性能研究[J].节水灌溉, 2010(5):1-4.
[6]陈雪,吴普特,范兴科,等.灌水器迷宫流道结构参数数值模拟与抗堵塞分析[J].灌溉排水学报, 2008, 27(2):35-38.
[7] XIE Q L, NIU W Q, LI L Z. Effect of tooth angle and pitch of labyrinth channel on performance of emitter[J]. Journal of Drainage&Irrigation Machinery Engineering, 2013, 31(5):449-455.
[8]喻黎明,吴普特,牛文全.迷宫流道偏差量对灌水器水力性能及抗堵塞性能的影响[J].农业机械学报, 2011, 42(9):64-68.
[9]唐学林,赵旭红,李云开,等.迷宫流道滴头内流场和颗粒运动的不同湍流模型数值模拟[J].农业工程学报, 2018, 34(16):120-128.
[10]张俊,魏公际,赵万华,等.灌水器内圆弧形流道的液固两相流场分析[J].中国机械工程, 2007, 18(5):589-593.
[11]喻黎明.迷宫流道灌水器CFD两相流数值模拟中固体颗粒参数的确定[J].长沙理工大学学报, 2011,8(2):51-55.
[12]喻黎明,梅其勇.迷宫流道灌水器抗堵塞设计与PIV试验[J].农业机械学报, 2014, 45(9):155-160.
[13] ZHANG J, ZHAO W H, TANG Y P, et al. Anti-clogging performance evaluation and parameterized design of emitters with labyrinth channels[J].Computers and Electronics in Agriculture, 2010, 74(1):59-65.
[14] WEI Q S, LU G, LIU J, et al. Evaluations of emitter clogging in drip irrigation by two-phase flow simulations and laboratory experiments[J]. Computers and Electronics in Agriculture, 2008, 63(2):294-303.
[15]魏正英,唐一平,温聚英,等.灌水器微细流道水沙两相流分析和微PIV及抗堵实验研究[J].农业工程学报, 2008, 24(6):1-9.
[16]王建东,李光永,邱象玉,等.流道结构形式对滴头水力性能影响的试验研究[J].农业工程学报, 2005, 21(z1):100-103.
[17]喻黎明.灌水器流道结构参数与水力性能关系[J].长沙理工大学学报(自然科学版), 2011(1):30-35.
[18]李云开,杨培岭,任树梅.滴灌灌水器流道设计理论研究若干问题的综述[J].农业机械学报, 2006, 37(2):145-149.
[2]穆乃君,张昕,李光永,等.内镶片式齿型迷宫滴头抗堵塞试验研究[J].农业工程学报, 2007, 23(8):34-39.
[3]芦刚,史玉升,魏青松,等.基于两相流模拟的高抗堵滴灌灌水器开发方法[J].华中科技大学学报(自然科学版), 2007, 35(7):118-121.
[4]马晓鹏,龚时宏,王建东,等.额定压力及低压下内镶片式滴头抗堵塞性能试验[J].农业机械学报, 2011, 42(7):86-90.
[5]武鹏,牛文全,常莹华,等.齿形迷宫流道不同结构参数下灌水器抗堵塞性能研究[J].节水灌溉, 2010(5):1-4.
[6]陈雪,吴普特,范兴科,等.灌水器迷宫流道结构参数数值模拟与抗堵塞分析[J].灌溉排水学报, 2008, 27(2):35-38.
[7] XIE Q L, NIU W Q, LI L Z. Effect of tooth angle and pitch of labyrinth channel on performance of emitter[J]. Journal of Drainage&Irrigation Machinery Engineering, 2013, 31(5):449-455.
[8]喻黎明,吴普特,牛文全.迷宫流道偏差量对灌水器水力性能及抗堵塞性能的影响[J].农业机械学报, 2011, 42(9):64-68.
[9]唐学林,赵旭红,李云开,等.迷宫流道滴头内流场和颗粒运动的不同湍流模型数值模拟[J].农业工程学报, 2018, 34(16):120-128.
[10]张俊,魏公际,赵万华,等.灌水器内圆弧形流道的液固两相流场分析[J].中国机械工程, 2007, 18(5):589-593.
[11]喻黎明.迷宫流道灌水器CFD两相流数值模拟中固体颗粒参数的确定[J].长沙理工大学学报, 2011,8(2):51-55.
[12]喻黎明,梅其勇.迷宫流道灌水器抗堵塞设计与PIV试验[J].农业机械学报, 2014, 45(9):155-160.
[13] ZHANG J, ZHAO W H, TANG Y P, et al. Anti-clogging performance evaluation and parameterized design of emitters with labyrinth channels[J].Computers and Electronics in Agriculture, 2010, 74(1):59-65.
[14] WEI Q S, LU G, LIU J, et al. Evaluations of emitter clogging in drip irrigation by two-phase flow simulations and laboratory experiments[J]. Computers and Electronics in Agriculture, 2008, 63(2):294-303.
[15]魏正英,唐一平,温聚英,等.灌水器微细流道水沙两相流分析和微PIV及抗堵实验研究[J].农业工程学报, 2008, 24(6):1-9.
[16]王建东,李光永,邱象玉,等.流道结构形式对滴头水力性能影响的试验研究[J].农业工程学报, 2005, 21(z1):100-103.
[17]喻黎明.灌水器流道结构参数与水力性能关系[J].长沙理工大学学报(自然科学版), 2011(1):30-35.
[18]李云开,杨培岭,任树梅.滴灌灌水器流道设计理论研究若干问题的综述[J].农业机械学报, 2006, 37(2):145-149.
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