【作者】 薛娇； 刘士和；

【Author】 XUE Jiao;LIU Shi-he;School of Water Resources and Hydropower Engineering,Wuhan University;

【机构】 武汉大学水利水电学院；

【摘要】 管流与明渠流同属流体力学中的内流,其总流机械能方程在水力学中称为能量方程。我们曾直接从黏性不可压缩流体运动的控制方程出发,经过推导,分别得到了管流及明渠流的总流机械能方程,在此基础上,将管流及明渠流在层流条件下的总流机械能方程进行了统一,并分别计算了管流(圆管、不同长短半轴比的椭圆管、不宽深比的矩形管)及明渠(不同宽深比明渠)在层流条件下的机械能损失系数。结果表明,在同一雷诺数条件下,圆管层流的机械能损失系数比椭圆管层流及较大宽深比的矩形明渠层流的机械能损失系数要小。更多还原

【Abstract】 Pipe flow and channel flow is internal flow in fluid mechanics.The mechanical energy equation is called energy equation in hydraulics.The energy equations for laminar pipe flow and laminar channel flow were deduced from the N-S equation in fluid mechanics respectively.The unified energy equation for total laminar flow in pipes and open channels is obtained and the mechanical energy losses are compared based on the existing results.The mechanical energy losses of laminar pipe flow(circular tube,oval tube with different semi-axes ratios and rectangular tube with different width-depth ratios) and laminar channel flow(open channel with different width-depth ratios) are calculated in this paper.The results show that the mechanical energy loss of circular tube is less than those of oval tube and open channel when the Reynolds numbers are equal.更多还原