多孔管的变径设计

The design for a multiple outlet pipeline with different diameters

在保证孔口压力差不超过允许范围条件下，一条多孔管可由两种管径不同的管段组成，即采用变径法设计。本文考虑了影响多孔管沿程压力的因素，导出了各种地形坡度下变径设计计算公式。这一方法可供喷灌及微灌工程设计参考。

A design procedure is presented for a multiple outlets pipeline which is composed of two segmentations with different diameters while the variation in pressure head is restricted to assure the required outlet discharge uniformity. According to factors affecting pressure head along pipeline, the equations are established to calculate segment length in different pipe slopes. The procedure is applicable both sprinkler and micro-irrigation systems.