Abstract:In order to investigate the variation of hydraulic performance of drip irrigation belts with jet tee connection, the hydraulic performance experiments of inlet flow rate and outlet head amplitude of jet tee was carried out in the range of 0.1-1.2 m3/h at the inlet of jet tee connection. It was found that the flow threshold of jet tee connected with pulse drip irrigation system was 0.2-0.8 m3/h. Pulse parameter experiment of drip irrigation belt connected jet tee along drip irrigation belts was carried out in the range of flow threshold of the pulsed drip irrigation system. The variation rule of pulse performance along drip irrigation belts of 60 m connected drip irrigation belt was studied. It was found that when the head amplitude of drip irrigation was greater than 1 m, there was a sudden change in the attenuation rate of head amplitude along drip irrigation belts. The pulse frequency along drip irrigation belts increases first and then decreases. The design range of the inlet flow of jet tee which can generate pulsed flow on the whole drip irrigation was 0.5-0.8 m3/h. A comparative experiment of steady-pressure drip irrigation and pulsed drip irrigation in the same stage was carried out within the design range of the inlet flow of jet tee. The results show that the head loss of drip irrigation belt in pulse drip irrigation system was reduced by 62.5%-83.3%, which lower than that under steady-state condition. The irrigation uniformity coefficient was increased by 0.6%-0.9%, and the flow deviational coefficient was reduced by 1.2%-4.1%, when compared with that in the ordinary tee joint drip irrgation belt. When the inlet flow is 0.7 m3/h, the irrigation uniformity of drip irrigation belt connected by jet tee was the maximum.