低压微灌多孔软管水力特性试验研究

Experimental Research on Hydraulic Characteristics of Low Pressure Micro-irrigation Perforated Flexible Hose

为了进一步探索低压微灌多孔软管的水力性能,采用室内试验方法,研究了低压(1～5m)条件下多孔软管的出流规律、沿程压力分布规律以及水头损失分布规律,结果表明,在低压条件下,多孔软管的水力特性受进口压力、出流孔孔距、铺设长度等因素影响,且受到管壁塑性变形的影响;沿程出流表现出单峰性,随管长及孔距增大,最大值点前移,随压力增大,沿程出流更为均匀;沿程压力一直减少,前半段减幅约为后半段的4倍,且随孔距增大,递减幅度变小;水头损失随孔距减小和压力增大而减小,且进口压力为1～3m时的减幅与4～5m时的比值在管长为40m时,其值约为管长为30m时的2倍。研究结果可为低压微灌技术的完善和发展提供理论依据。

In order to seek the hydraulic characteristics of low pressure micro-irrigation perforated flexible hose fatherly,an experimental research on the law of pressure distribution,outflow distribution and head loss distribution along flexible hose at low pressure（1~5 m） is conducted in this paper.The results show that under the condition of low pressure,the hydraulic characteristics of perforated flexible hose are affected by inlet pressure,outlet orifice interval and laying length,as well as the plastic deformation of tube wall;the outflow along the hose shows unimodality;the maximum value point moves forward with the increase of hose length and the outlet orifice interval;the outflow along the hose become more uniform with greater inlet pressure;the pressure head distribution decreases along the hose;the reduced rate in first half is 4 times of that in second half,but the decreasing range becomes smaller with the increase of orifice interval.Meanwhile,the head loss decreases with the decrease of orifice interval and the increase of inlet pressure,the ratio of the reduced rate with inlet pressure 1~3 m to 4~5 m,when hose length is 40 m,is about 2 times of that when the hose length is 30 m.Therefore,the results can provide some theoretical basis for the improvement and development of low pressure drip irrigation.