入汇主河的泥石流龙头运动机理研究

作者基于野外观测资料和模型试验，提出了泥石流与主河交汇的两种模式，即：有上下分层交汇和无明显分层的潜入式交汇。建立了潜入式交汇的泥石流龙头运动方程，并讨论了模型参数的取值。计算结果得到以下结论：当主河水流费劳德数比较小(Fr＜0.35)时，入汇主河泥石流龙头在主河的运动速度近似以线性减速，且与试验值吻合较好；混合流粘滞系数和绕流系数对龙头运动速度影响较大；泥砂沉降速度对龙头内部体积比浓度有显著影响。

Movement of debris flow head in main channel at the confluence

Based on field observation and experiment the movement patterns of debris flow into main channel at the confluence are classified into two kinds:stratified flow and submerged flow. The equation for describing the movement of debris flow head in submerged flow pattern is established and the method for determining the corresponding parameters is proposed. The numerical calculation shows that the velocity of the head of submerged debris flow is decelerated following a linear rule, in case the Froude number of the flow in main channel is less than 0.35. This result is in good agreement with experiment data. The viscosity and drag coefficient may remarkably affect the velocity of debris flow head and the setting velocity of sediment will greatly affect the concentration of the debris flow head body.