地下滴灌毛管水力要素试验

Hydraulic factors of laterals in subsurface drip irrigation

地下滴灌毛管滴头的压力和流量分布是其主要的水力要素,研究这一问题对地下滴灌工程的设计和运行管理具有重要的意义。该文提出了地下滴灌毛管水力要素的试验方案,可用较短毛管获得其压力流量测试数据和分布规律。针对提出的试验方案,结合地下滴灌单滴头的水力特性研究成果,建立了描述地下滴灌毛管压力、滴头流量和局部水头损失系数之间关系的非线性方程组。将这一非线性方程组计算转化为一个函数优化问题,建立其求解的优化数学模型,采用遗传算法求解。用试验数据验证了计算结果,表明用此非线性方程组可反映地下滴灌毛管压力流量分布规律,求解方法具有较高的计算精度。该方法为进一步研究地下滴灌毛管的水力要素奠定了基础。

A thorough understanding of pressure and discharge along lateral is needed for efficient design and operation of subsurface drip irrigation （SDI） .Test data and distribution of pressure and emitter discharge were obtained by using shorter lateral based on the experiment plan of SDI lateral hydraulic factors .The nonlinear equations describing lateral pressure, emitter discharge and local head loss factor coefficient were established based on the test data and research results of single emitter hydraulic characteristics in SDI. Calculation of nonlinear equations had been translated into the function optimization problem, and the optimization mathematical model was established, the genetic algorithms was adopted to solve the model. The calculated result was validated by test data, and it indicated that the distribution of pressure and discharge along SDI lateral could be described with the nonlinear equations and solution method had the high calculation accuracy. This method lays the foundation of further study the hydraulic factors of SDI lateral.