【摘要】 作者应用尖点突变理论的坐标变换和拓扑变换 ,导出了非均匀沙起动时的尖点突变模式 ,即希尔兹数和沙粒雷诺数的函数关系式。文章将希尔兹数作为尖点突变模型的状态变量 ,沙粒雷诺数的负 0 3次方和无量纲参数mdm d0 作为控制变量。用水槽试验资料对水流切应力τ0 与起动粒径d0 的函数关系式进行了验证。验证结果表明 ,计算值与水槽试验结果基本相符。在d0 较大时 ,误差 1%～ 30 %之间 ;起动粒径d0 较小时 ,最大误差为76 2 %。说明本文建立的尖点突变模式是合理的 ,能够反映非均匀泥沙的起动的规律。更多还原

【Abstract】 The authors derived a relation formula between Shields number and Reynolds number of sediment by using the coordinate transform and topology transform.The Shields,number was regarded as the state variable and the Reynolds number of sediment and the non dimensional number m d m/d 0 as the bound variables in the cups catastrophe model.The computed results by using the model were in good agreement with the test data in a water flume.The error was comparatively small(1%～30%)when the entrainment diameter. d 0 of sediment is large and it would be big(up to 76 2%) when d 0 is small.It indicates that the cups catastrophe formula is reasonable and able to reflect hte charcteristics of threshold motion of non uniform sediment.更多还原