灌水均匀度是衡量滴灌系统灌水质量和水力设计的重要指标，为探究低压条件下提高灌水均匀度的方法，试验以压力补偿内镶式滴灌带和压力补偿圆柱式滴灌管为材料，测定不同毛管入口压力、敷设长度、灌水器间距的滴头流量分布及灌水均匀度。结果表明，在低压条件下，滴灌灌水均匀度随毛管入口压力的增大及敷设长度的降低而提高，随灌水器间距的增大而缓慢降低，其中毛管敷设长度影响最大，毛管类型次之，灌水器间距最小，当两种滴灌毛管入口压力在2~5m时，灌水均匀度均高于85%，且随入口压力的减小而缓慢降低，入口压力在0.5~2m时，灌水均匀度显著降低，压力补偿内镶式滴灌带灌水均匀度低于80%，但压力补偿圆柱式滴灌管灌水均匀度仍高于80%；当两种滴灌毛管敷设长度在40~70m时，灌水均匀度均高于85%，且随敷设长度的增大而缓慢降低，敷设长度在70~90m时，灌水均匀度显著降低，当压力补偿内镶式滴灌带和压力补偿圆柱式滴灌管的敷设长度分别大于75m、85m时，灌水均匀度均低于80%。因此，为了满足设计要求，压力补偿内镶式滴灌带入口压力不低于2m，敷设长度控制在75m以内；压力补偿圆柱式滴灌管入口压力不低于0.5m，敷设长度控制在85m以内；为了降低投资成本，可以适当增大滴灌毛管灌水器间距。

Irrigation uniformity is an important index in measuring the irrigation quality and hydraulic design of the drip irrigation system. In order to search the way to improve irrigation uniformity under low-pressure, pressure-compensated inner drip irrigation tape and pressure-compensated cylindrical drip irrigation tube were used in the experiment to measure different lateral inlet pressure, lateral length, emitter flow distribution in the space between irrigators and irrigation uniformity. The experiment result shows that irrigation uniformity would increase as lateral inlet pressure increased and lateral length decreased, and slowly decrease as the space between irrigators increased. Lateral length had the greatest impact on the uniformity of irrigation, with lateral type and the space between irrigators ranked second and third respectively. When the inlet pressure of two types of drip irrigation lateral was 2~5m, irrigation uniformity was higher than 85% and decreased slowly with the decrease of inlet pressure. While the inlet pressure was 0.5~2m, irrigation uniformity was significantly reduced, and the pressure-compensated inner drip irrigation tape was less than 80%, but the pressure-compensated cylindrical drip irrigation tube was still higher than 80%. When the lateral length of two types of drip irrigation lateral was 40~70m, irrigation uniformity was higher than 85% and decreased slowly with the increase of lateral length. While the lateral length was 70~90m, irrigation uniformity was significantly reduced, and the pressure-compensated inner drip irrigation tape and pressure-compensated cylindrical drip irrigation tube was more than 75m and 85m respectively, irrigation uniformity was less than 80%. Therefore, in order to meet the requirements of engineering design, which drip irrigation uniformity is not less than 80%, the pressure-compensated inner drip irrigation tape inlet pressure is higher than 2m, lateral length is limited to 75m; the pressure-compensated cylindrical drip irrigation tube inlet pressure is higher than 0.5m, lateral length is limited to 85m; it is practical to increase the space between irrigators to reduce engineering investment effectively.

为研究不同流量下渐扩段局部水头损失规律,选取了MIKE软件的水动力(HD)模块,对渐扩段水面线进行模拟分析,从而得出局部水头损失的水面线、流场等相关规律,并与计算值进行对比。计算结果表明:模拟得到的渐扩段沿程水面线与计算值吻合较好,且从流场图上及水位对比图中可看出,MIKE软件更能很好地模拟出局部水头损失,大大减小计算的难度和复杂程度,且能做到精确模拟。研究成果可为相关实际水利工程提供依据。

The water surface profile of gradually broadened channel is simulated with HD (hydrodynamic) model in MIKE software, and the change rules of water surface profile and flow field of local head loss are obtained. The simulation results are compared with results calculated by empirical formula, and the conclusion reveals that the simulated water surface profile of gradually broadened channel agrees well with the calculation result; MIKE could better simulate the local head loss by reducing the difficulty and complexity of formula calculation, hence achieving a precise simulation.

本研究采用国内4种常规内镶贴片式滴灌带，分别在低压（10 ~60 kPa）和常压（100~160 kPa）两种供水模式下进行了滴头水力性能的对比试验研究，结果表明：常规滴灌带在低压与常压模式下的水力性能存在一定的差别，不同压力模式对常规滴灌带的流态指数x、流量偏差系数Cv均具有一定影响。在低压模式下，A、B、C型滴灌带较常压模式下x分别增大9.03%、0.41%、17.70%， D型滴灌带较常压模式下x减小13.48%，D减小幅度最大，适合在低压模式下运行； A至D型滴灌带较常压模式下Cv分别增大23.34%、10.63%、24.89%、0.82%，低压模式下滴头流量均匀性较常压模式下稍差，但也满足滴灌带质量为优等的要求。采用1stOpt对低压模式下4种滴灌带压力~流量关系式进行模拟， R2均大于0.9，模拟效果较好。