压力补偿滴头抗堵塞性的数值模拟研究

Numerical simulation of anti-clogging performance of pressure compensating emitter

【目的】用数值模拟方法研究压力补偿滴头的抗堵塞性,为灌溉滴头的结构改进提供参考。【方法】以孔口式压力补偿滴头为对象,综合运用流固耦合与液固两相流的数值模拟方法,分析压力补偿滴头在不同入流颗粒粒径(0.01,0.02,0.04和0.06mm)及体积分数(0.2%,0.4%,0.6%,0.8%,1.0%和1.2%)下,压力补偿滴头的内流场及颗粒体积分数分布规律。【结果】在供试颗粒粒径及体积分数范围内,压力补偿滴头流道内局部颗粒体积分数升高,容易发生沙粒沉淀;同一位置处水的速度较固体颗粒大;随着入流颗粒粒径及体积分数的增大,滴头出流量略有减少,但仍达清水流量的94.7%以上;入流颗粒体积分数相同时,颗粒粒径越大,流道内最大颗粒体积分数越大。【结论】改进压力补偿滴头环形流道的入口结构能提高其抗堵塞性;提高灌溉系统抗堵塞性需同时提高滴头抗堵塞性并改进过滤设施。

【Objective】 Study was made on the anti-clogging performance of pressure compensating emitter provide references for optimization design of pressure compensating emitter.【Method】 Based on fluid-structure interaction and two phase flow theory,the paper analyzed the distribution of inter-liquid field and granule volume fraction under different granule diameters（0.01,0.02,0.04 and 0.06 mm） and initial volume fraction（0.2%,0.4%,0.6%,0.8%,1.0% and 1.2%） in a pressure compensating emitter.【Result】 The results show that,within the scope of the study,the granule volume fraction increases in the local channel.Water velocity is larger than granule’s in the same position.Though it reduced with the increase of granule diameter or initial volume fraction,the flow rate still is 94.7% greater than clean water’s.When initial volume fraction keeps the same,the max granule concentration increases with the increase of granule diameter.【Conclusion】 In general,the anti-clogging performance changes with the change of the inlet structure of pressure compensating emitter.Improving the anti-clogging of irrigation systems needs the improvement of filtration facilities as well as anti-clogging of the emitter.