Numerical simulation of influence of tooth angle on hydraulic characteristics of labyrinth emitter
ZHANG Chuanjie1,2, NIU Yong3*, LIU Xiaohang2
1. Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Water Saving Agriculture of Henan Province, Xinxiang, Henan 453002, China; 2. College of Water Conservancy and Civil Engineering, Shandong Agricultural University, Taian, Shandong 271018, China; 3. Forestry College, Shandong Agricultural University, Taian, Shandong 271018, China
Abstract：In order to explore the influence of the tooth angle of the labyrinth channel on the hydraulic characteristic of emitters, the numerical analysis method of the CFD was used to investigate the influe-nce of tooth angles(50°, 60°, 70°, 80°)of orthodontic-tooth and oblique-tooth labyrinth channels of emitters on flow and velocity field. The results showed that compared with the RNG k-ε model and the SST model, the calculation results of the standard k-ε model are closer to the experimental results. There are mainly two low velocity recirculation areas in the labyrinth channel, namely the upper left side and the lower right side of the labyrinth emitters. Compared with the orthodontic-tooth labyrinth channel, the oblique-tooth labyrinth channel has more low-speed areas on the upper left side and fewer low-speed areas on the lower right side. As the increase of the tooth angle, the flow rate in the emitter increases continuously, especially for the oblique-tooth labyrinth channels, and the increase of the flow rate in the Labyrinth emitter with helical teeth is more obviously affected by the angle between teeth. The flow coefficient of the labyrinth emitter with regular teeth is larger, but the flow pattern index is smaller. The flow index of the orthodontic-tooth labyrinth emitter with an angle of 70° is the smallest among all emitters, so the flow rate of this emitter is the least sensitive to the pressure changes. Compared with other labyrinth-tooth emitters, this emitter has the best hydraulic performance.
