直管阻力测定中Re－λ关系曲线测定方法探究

针对Ｒｅ－λ关系曲线绘制得很短而不理想的问题，笔者提出设计流量测压降的方法，并重新设计了直管阻力－分支管路综合实验装置。利用分支管路上的转子流量计测量小流量，对小流下压差测量另外配置了四氯化碳为指示液的压差计。使Ｒｅ值由原来的８６１００～１３７０００变为４０００～１２８０００，测实验点９个。实验结果显示，曲线大大延长，并符合教学要求。

Exploration of the Measurement of Re-λ Chart in the Determination of Straight Pipe Resistance

It is aimed at the problems of the Re-λ chart plotting which is very short and not so perfect, the authors put forward the method of designing flow rate for the pressure drop measuring, and a multiple experimental device for the straight pipe resistance branching pipe is designed again. The amall flow rate is measured by a rotameter on line with the branch, and the other differential manometer with carbon tltrachloride as the index medium is disposed for the lower pressure difference measuring to the small flow rate. The original value Re Change from 86 100￣137 000 to 400￣128 000 while the experinental data are 9. The experimental results show that the curve is extended obviously and accords with the teaching demands. It has been trying in 23 classes and achieves the desired results.