膜片对压力补偿灌水器水力性能影响及内部流固耦合模拟

为了研究弹性膜片参数对管上式压力补偿灌水器水力性能的影响和内部补偿腔压力补偿原理,以Supertif-03120-0003型号的压力补偿灌水器为原型件,通过3D打印技术制作管上式灌水器试验件,测试入口压力为0~350 k Pa时的压力-流量曲线,分析弹性膜片(天然橡胶材质)的厚度与硬度对其水力性能的影响;借助ADINA软件,采用流固耦合的计算方法,分析了压力补偿灌水器内部补偿原理及水力性能.结果表明:弹性膜片厚度一定,随着硬度增加,灌水器的出流量和起调压力均呈现增大的趋势;弹性膜片硬度一定,随着厚度增加,灌水器的出流量和起调压力均呈现增大的趋势,在起调压力点之后,灌水器出流量的增长速率减慢,最终压力-流量曲线趋于平缓.在此灌水器内部结构下,膜片参数存在最优选择,即厚度为1.4 mm,硬度为50HA;压力-流量关系的数值模拟值与实测值比较接近,两者最大偏差小于5%,说明采用ADINA软件模拟得出的压力-流量关系与实测值具有较好的一致性.该方法为压力补偿灌水器的进一步研发提供了可视化途径.

Influence of elastic diaphragm on hydraulic performance of pipe-type pressure compensating emitter and simulation of internal fluid structure interaction

In order to study the influence of elastic diaphragm parameters on the hydraulic performance of pipe-type pressure compensating emitter and the internal compensating principle of compensation pressure chamber, the pressure compensating emitter of type supertif-03120-0003 is used as the prototype and a pipe-type emitter experimental model is fabricated with 3D printing. The pressure-flow curve of the model was measured at inlet pressures ranged in 0-350 kPa. The effects of thickness and hardness of the natural rubber elastic diaphragm on the hydraulic performance of the emitter were analyzed. A fluid-structure interaction(FSI)analysis on the compensating principle and hydraulic performance in the emitter was launched in ADINA software. The results showed that when the thickness of the elastic diaphragm was constant, the discharge flow and compensating threshold pressure of the emitter all increased with increase of the elastic diaphragm hardness. When the hardness was fixed, the discharge flow and compensating threshold pressure both showed an increasing trend with increase of the thickness. The growth rate of the emitter discharge flow was decreased beyond a threshold pressure, and finally the pressure-flow relationship curve tended to be flat. For this internal structure of the emitter, the elastic diaphragm was subject to an optimal combination of hardness and thickness, namely thickness 1.4 mm, hardness 50HA. The predicted pressure-flow curve was in good agreement with the measured value, and the maximum deviation between them was less than 5%, indicating that ADINA software was proper in FSI analysis of compensating principle and hydraulic performance for the emitter. This method has provided a visualization way for research and development of emitters with pressure compensation.