阻力系数的研究

Study on Resistance Coefficient

摘要: 本文对尼库拉兹、穆迪和蔡克士达等三个阻力系数图作了评述，指出了这些图中存在的问题。文中指出，在矩形明渠中不存在像尼库拉兹那样形式的阻力系数图。只有在二维明渠中，才存在像尼库拉兹那样形式的阻力系数图，并在文中给出了二维明渠均匀流的阻力系数图。利用所给图中粗糙平面上的阻力系数公式，计算了二维粗糙渠道均匀流的流速，并和蔡克士达的宽浅矩形渠道中的试验结果相比较，差值在4%以内。

Abstract: In this paper, the resistance coefficient diagrams of Nikuradse, Moody and Segsda were discussed. The discussions showed that resistance coefficient diagram as the Nikuradse’s form cannot exist in rectangular open channel. Only in the two-dimensional open cannel flow, the resistance coefficient diagram as the form of Nikuradse exists. In this paper, this resistance coefficient diagram was given. Using the resistance coefficient equation on the rough plate of the diagram, the velocity of uniform flow of the two-dimensional rough channel was computed. Comparing the results with those of Segsda’s wide shallow rectangular channel experiment, the difference is within 4%.