Design And Experimental Research On Aeration Impact Sprinkler

The research of aeration impact sprinkler is supported by The National Science Foundation of China“Study on Dispersion Characteristics of Low-Pressure Water Jet based on Aeration Method”?NO:51379090?.Aeration impact sprinkler is a new multifunctional application equipment with the gas-liquid two-phase jet.It can not only be self-primed with gas and liquid to turn the multifunctional application into reality and improve hydraulic performance but also adapting to the trends of multifunctional application and the development direction of saving energy because of simple structure and manufacturing expediency.In clarification of the problematic of impact sprinkler with low pressure engrossed water flow excessively on the end of the water jet,with 20PY₂ and 30PY₂ aeration impact sprinkler,research of this paper mostly comprises the result of the sprinkler through gas and liquid into aeration structure and the condition of hydraulic enhanced by gas volume.Themodification of the water jet after the impact sprinkler with gas confirmed by the high-speed photography experiment and the condition of irrigation improved with gas after this sprinkler carried out to combination irrigation.?1?Based on the structure of impact sprinkler,the aeration structure is designed and the gas-liquid two-phase jet is formed in the same water flow.According to the national standard‘Rotating sprinkler',compared with the effect of impact sprinkler combination irrigation,the working pressure range of the two types of aeration impact sprinkler can be reduced by 100kPa.?2?Hydraulic performance and suction performance of aeration impact sprinkler were affected by the fact including Pipe inner diameter,a telescopic distance of the pipe and angle of the nozzle.Blocking secondary nozzle,test structure of sprinkler recommended as,the angle of the nozzle was 38°,the telescopic distance of the pipe was 2 mm,the inner diameters of the pipe was 2 mm?20PY₂?and 4 mm?30PY₂?.In the same working condition,comparing with impact sprinkler aeration impact sprinkler with gas had the same range and the range of liquid was less about1m.With the working pressure increasing,the volumes of gas and liquid were increasing but their increment decreases,and the curves of liquid-gas ratio and liquid-liquid ratio decreases.The sprinkler with gas and liquid and result of adding air was effective to improve the water delivery and decrease the concentration at the end of the water jet.When 20PY₂ aeration impact sprinkler simulated the experiment of combination irrigation,the best combination distance is 1.2 R with liquid,and the average value of the irrigation uniformity coefficient was 80%.?3?Using methods of the high-speed photography and image processing to study gas-liquid two-phase jet initial period of 20PY₂ aeration impact sprinkler,the unceasing gas-pulsation of the nozzle exit was observed.Under 200 kPa and 300 kPa working pressure pulsation frequency were respectively about 73Hz and 140Hz,and the frequency increases with working pressure.Under different working pressure,the fitting empirical formula between the length of the jet breakup and the range of the jet flow were obtained,which is used to compare the characteristic length values of the gas-liquid two-phase jet.?4?Under low pressure,when the wind speed was 1m/s,the evaporation and drift of 20PY₂ aeration impact sprinkler was about 5%.The simulation value and test value deviation of the average sprinkler intensity of this sprinkler were kept between5%and 9%.The average value of irrigation uniformity coefficient of this sprinkler is higher about 80%than impact sprinkler.Combined with the effect of work pressure and combination distance influence on combination irrigation,the relationship between CU and DU_lq,DU_hq,DU_lh,DU_hhh and the test value of sprinkler intensity were compared,which were confirmed at the low pressure that the best working pressure of this sprinkler is 300 kPa,the best combination distance is 1.1 R.