阻力系数的研究

Study on resistance coefficience

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 coefficience diagrams of Nikuradse, Moody and Segsda are disussed. The discussions show that resistance coefficient diagram of segsday as the Nikuradse’s form cann’t exist, only the two dimension of open channel flow exists the resistance coefficient diagram as the form of Nikuradse diagram. In this paper, this resistance coefficient diagram is given. With this diagram, the velocity of the two dimensional open channel uniform flow on the rough plate is computed. The computation result is comcidence with the experiment value of Segsda for shallow water flow.