Abstract:In order to improve the hydraulic performance of three-way pulse jet tee and the uniformity of drip irrigation, the structure of a three-way pulse jet tee with 15 mm inlet width is optimized based on CFX numerical simulation technology. The half difference in width between nozzle and tee inlet s, distance between tee inlet and daughter branch inlet H, daughter branch wall curvature radius r and tee inlet wall inclination angle β were selected as influencing factors, then nine cases were generated by using four-factor and three-level orthogonal design table. A 100 kPa inlet pressure was used as the boundary condition and the flow rate through the daughter branches was served as the evaluation criterion. The optimum structural dimensions of the three-way jet tee are s=5.5 mm, H=113 mm, r=13 mm and β=10°. A hydraulic performance test was conducted on this optimized three-way jet tee. When the inlet water pressure is 100 kPa, the pulse frequency of the jet in the tee is 148 min-1, the hydraulic head amplitude is 37.9 kPa, the hydraulic head loss is 16.7 kPa, and the outlet flow rate is 0.698 L/s. When the tee is connected with a 60 m long drip irrigation tape, the uniformity coefficient of irrigation is improved by 2.78% and the flow rate deviation is lowered by 4.72% in comparison with the ordinary three-way tee. This study can provide a theoretical basis for research, development and application of the pulse jet drip irrigation system.