用有机玻璃制成两类并联管组模型,一类为支管和集管平滑相连接的正常型,另一类为支管伸入集管约6mm 的支管伸入型。在入口处注入墨汁,观察并联管组中的流动分布,正常型管组的流动分布和数值计算结果相一致,支管伸入型管组的某些支管中产生倒流现象。对于倒流的原因作了初步的分析。 Plexiglass made with two types of parallel pipe model, one for the branch and header smooth connection of the normal type, the other branch into the header into the tube about 6mm branch extension type. Ink was injected into the entrance to observe the flow distribution in the parallel pipe group. The flow distribution of the normal pipe group was consistent with the numerical calculation results. Backflow phenomenon occurred in some branch pipes of the extended pipe group. The reasons for the backwash made a preliminary analysis.