摘要
基于射流附壁与换向原理设计出一种能够在两个出口产生振荡水流的射流振荡三通，射流振荡三通的两个出口后面分别连接毛管后，能够使水流在两条毛管内按照一定频率间歇性流动，在毛管内产生脉冲水流，可以构建新型的脉冲滴灌系统。在分析射流振荡三通工作原理的基础上，确定了两组射流振荡三通的参数：喷嘴宽度W=5mm和W=4mm，并加工成试验样件，进行了射流振荡三通与毛管脉冲的初步试验研究。试验结果表明：在进口压力为50~120kPa条件下，水流经过射流振荡三通后，每组射流振荡三通都能够产生振荡水流；在每组射流振荡三通两个出口后面各连接一条60m长的毛管，可明显观测到毛管内产生的脉冲水流，在进口压力50～120kPa条件下，W=5mm与W=4mm的毛管进口压力脉冲幅度均在30kPa以上，脉冲频率都为3．6～4．0Hz。通过对比可知，喷嘴宽度越大，脉冲振幅就越大，脉冲频率就越小。
A kind of jet oscillation tee was originally designed based on the coanda effect and the reversing theory. The jet oscillation tee can produce an oscillatory flow under a certain frequency in the two branches, thus transmits a pulse flow in the following lateral pipes, which can be used as a new type of pulse drip irrigation system. Based on the analysis of working principal of the jet oscilla- tion tee, two groups of structural parameters were determined, namely the nozzle diameter W=5 mm and W=4 ram, and then a test sample was made. A preliminary experimental investigation was performed on the feasibility of the jet oscillation tee and the pulse characteristics of lateral pipe. The results demonstrated that an oscillatory flow arised in each jet oscillation tee under the inlet pres- sure 50~120 kPa. A pulse flow was observed in each lateral pipe with 60 m length connected to the two outlets of each jet oscillation tee. Under 504120 kPa inlet pressure, the pulse amplitudes of inlet pressures of the lateral pipes were all higher than 30 kPa and the pulse frequencies were 3.6~4. 0 Hz when the jet width of the nozzles were W=5 mm and W=4 ram. Through the comparison, it could be found that the bigger the nozzle diameter, the larger the pulse amplitude and the lower the pulse frequency.
出处
《节水灌溉》
北大核心
2014年第3期1-4,8,共5页
Water Saving Irrigation
基金
国家高技术研究发展计划("863"计划)资助项目(2011AA100506)
江苏省科技支撑计划(BE2013403)
关键词
射流振荡三通
滴灌
毛管
脉冲特性滴灌
jet oscillation tee drip irrigatiom lateral pipel pulse water characteristics
