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.
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