Optimization design of triangular labyrinth channel in drip irrigation emitter
Guo Lin1, Bai Dan1, Cheng Peng2, Zhou Wen2
1.Faculty of Water Resources and Hydroelectric Engineering, Xi′an University of Technology, Xi′an, Shaanxi 710048, China; 2.School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450011, China
Abstract：In order to study the hydraulic properties of triangular labyrinth channels in drip irrigation emitter, a basic structure of the channels is specified and severed as the investigational model which is defined by the three geometrical parameters such as turning angle, width and height of triangular labyrinth channel. Then, 10 cases are designed based on these parameters by means of uniform design method. Computational fluid dynamics software Fluent 6.2 is adopted to simulate the flow field in the channel of emitters numerically. The geometrical model is generated for each case by using 3D software AutoCAD. Subsequently, the flow in each model is simulated by making use of CFD software Fluent 6.2 to analyze the hydraulic performance and flow characteristics of the model and to obtain flow visualization pictures. Additionally, the flow rate is extracted and correlated to the pressure drop across the model by employing linear regression method, and an index is established for flow pattern. A mathematical relationship between the index and the geometrical parameters is developed based on the results of 10 cases by using multivariable linear regression approach. The genetic algorithm is adopted to optimize the three parameters by minimizing the flow index. The optimized triangular labyrinth channel is subject to an excellent hydraulic performance, namely uniform velocity profile and steadily reduced pressure distribution, and the flow rate through it is in an allowable range as well. This optimized channel can be a reference case for parameterized design, precision control of geometrical parameters in manufacturing and final research and development of triangular labyrinth channel in drip irrigation emitter.
[1]王新坤,李俊红,单彬,等.三角绕流滴灌灌水器结构设计和优化[J].农业机械学报,2010,41(增刊):43-46. Wang Xinkun, Li Junhong, Shan Bin, et al. Structural design and optimization of triangle circulation drip irrigation emitters[J]. Transactions of the Chinese Society for Agricultural Machinery, 2010,41(S1):43-46.(in Chinese)[2]Yildirim G, Agiralioglu N. Linear solution for hydraulic analysis of tapered microirrigation laterals[J]. Journal of Irrigation and Drainage Engineering, 2004,130(1):78-87.[3]Yan Haijun, Ou Yangjun, Nakano K, et al. Numerical and experimental investigations on internal flow characteristic in the impact sprinkler[J]. Irrigation and Drainage Systems, 2009, 23(1): 11-23.[4]Paxson G, Savage B. Labyrinth spillways: Comparison of two popular U.S.A. design methods and consideration of non-standard approach conditions and geometries[C]//Proceedings of the International Junior Researcher and Engineer Workshop on Hydraulic Structures. Brisbane, Australia: The University of Queensland, 2006:37-46.[5]Al-Muhammad J, Tomas S, Ait-Mouheb N, et al.μ-PIV characterization of the flow in a milli-labyrinth-channel used in micro-irrigation[C]//Proceeding of 17th International Symposium on Applications of Laser Techniques to Fluid Mechanics. Lisbon, Portugal:[s.n.], 2014: 1-15.[6]Vekariya P B, Subbaiah R, Mashru H H. Hydraulics of microtube emitters: A dimensional analysis approach[J]. Irrigation Science, 2011, 29(4): 341-350.[7]Aydin M C, Emiroglu M E. Determination of capacity of labyrinth side weir by CFD[J]. Flow Measurement and Instrumentation, 2013,29:1-8.[8]Ali A A M. Anti-clogging drip irrigation emitter design innovation[J]. European International Journal of Science and Technology, 2013,2(8):154-160.[9]Agostini B, Watel B, Bontemps A, et al. Liquid flow friction factor and heat transfer coefficient in small channels: An experimental investigation[J]. Experimental Thermal and Fluid Science, 2004,28(2):97-103.[10]王立朋,魏正英,邓涛,等. 压力补偿灌水器分步式计算流体动力学设计方法[J]. 农业工程学报,2012,28(11):86-92. Wang Lipeng, Wei Zhengying, Deng Tao, et al. Step-by-step CFD design method of pressure compensating emitter[J]. Transactions of the CSAE, 2012,28(11):86-92.(in Chinese)[11]Wei Zhengying, Cao Meng, Liu Xia, et al. Flow behaviour analysis and experimental investigation for emitter micro-channels[J]. Chinese Journal of Mechanical Engineering, 2012,25(4):729-737.[12]王新坤,李俊红,李亚飞,等.基于正交试验的三角环流流道灌水器数值模拟[J].排灌机械工程学报,2010,28(5):444-448. Wang Xinkun, Li Junhong, Li Yafei, et al. Numerical calculation of triangle circulation drip irrigation emitters based on orthogonal experiment[J]. Journal of Drainage and Irrigation Machinery Engineering, 2010,28(5):444-448.(in Chinese)[13]李云开,冯吉. 滴灌灌水器内部水动力学特性测试研究进展[J].排灌机械工程学报,2014,32(1):86-92. Li Yunkai, Feng Ji. Progress in measurement of hydrodynamic characteristics in drip irrigation emitters[J]. Journal of Drainage and Irrigation Machinery Engineering, 2014,32(1):86-92.(in Chinese)[14]李云开,杨培岭,任树梅,等.分形流道设计及几何参数对滴头水力性能的影响[J].机械工程学报,2007,43(7):109-114. Li Yunkai, Yang Peiling, Ren Shumei, et al. Effects of fractal flow path designing and its parameters on emitter hydraulic performance[J]. Chinese Journal of Mechanical Engineering, 2007,43(7):109-114.(in Chinese)[15]Wu Dan, Li Yunkai, Liu Haisheng, et al. Simulation of the flow characteristics of a drip irrigation emitter with large eddy methods[J]. Mathematical and Computer Modelling, 2013, 58(3/4): 497-506.[16]刘春景,郑加强,周宏平,等. 滴灌滴头水力性能预测模型[J]. 水利学报,2010,41(11):1353-1359. Liu Chunjing, Zheng Jiaqiang, Zhou Hongping, et al. Prediction model for hydraulic performance of trickle irrigation emitters[J]. Journal of Hydraulic Engineering, 2010,41(11):1353-1359.(in Chinese)[17]Palau Salvador G, Arviza Valverde J, Bralts V F. Hydraulic flow behaviour through an in-line emitter labyrinth using CFD techniques[C]//Proceeding of 2004 ASAE/CSAE Annual International Meeting. Ottawa, Canada: ASAE/CSAE, 2004:3127-3135.[18]Yildirim G. Hydraulic analysis and direct design of multiple outlets pipelines laid on flat and sloping lands[J]. Journal of Irrigation and Drainage Engineering, 2006,132(6):537-552.[19]Celik H K, Karayel D, Caglayan N, et al. Rapid prototyping and flow simulation applications in design of agricultural irrigation equipment: Case study for a sample in-line drip emitter[J]. Virtual and Physical Prototyping, 2011,6(1):47-56.
