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利用概化沙波模型,研究了不同坡度、粒径及位置情况下的泥沙起动流速,根据实测数据指出沙波泥沙起动流速特征,并分析比较了与平坡起动的差别。通过对泥沙颗粒的受力分析,提出水流冲击力,并利用沙波垂线流速分布公式进行流速换算,建立了沙波泥沙起动流速计算公式。结果表明:在相同水流条件下,因沙波地形影响,迎流面泥沙起动流速值小于平坡;沙波不同位置处的泥沙起动流速非定值,随着水平位置而变化;坡度和粒径对再附点附近泥沙起动流速影响较小。通过验证比较表明,公式计算结果与实测资料基本一致,适用于描述沙波迎流面泥沙起动规律,可反映出沙波坡度和水平位置的影响。
The generalized sand wave model is used to study the sediment flow velocity under different slope, particle size and location. According to the measured data, the sediment flow characteristics of sand sediment are pointed out, and the differences between them are analyzed and compared. Based on the force analysis of sediment particles, the paper puts forward the impact force of water flow, and calculates the flow velocity of sand sediment by using the formula of sand wave vertical velocity distribution. The results show that under the same water flow conditions, the flow velocity of sediment in the Yingtzu surface is smaller than that in the flat slope due to the influence of the sand wave topography. The velocity of the sediment in different positions of the sand wave is not fixed, and varies with the horizontal position. The particle size has little effect on the sediment flow velocity near the reattachment point. The results show that the formulas are basically consistent with the measured data, which is suitable for describing the law of sediment start-up on the sand flow Ying-Ying flow surface, which can reflect the influence of sand wave slope and horizontal position.