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应用大涡模拟方法对不同条件下单喷嘴垂直撞击射流的流场特性进行了数值模拟，对数值模拟结果的分析研究表明，在射流撞击距离小于射流等速核长度的条件下，射流撞击距离和喷嘴出口面积的变化对井底漫流层的厚度没有明显影响。提出了采用井底有效漫流层厚度和有效平均漫流速度研究水力作用对井底和钻头的清洗及冷却效果的新概念。研究表明，就ＰＤＣ钻头而言，减小钻头面至井底的距离，对提高整个井底的有效平均漫流速度，效果并不明显。
The large-eddy simulation method is used to simulate the flow field of a single-jet vertical impinging jet under different conditions. The numerical simulation results show that when the impinging distance is less than the jet constant-velocity core length, The change of nozzle outlet area has no significant effect on the thickness of the bottomhole flow layer. The new concept of hydraulic effect on the bottom hole and drill bit cleaning and cooling effect is proposed based on the effective bottom hole velocity and effective average velocity. The research shows that in the case of PDC bits, reducing the distance from the bit face to the bottom of the hole has no obvious effect on increasing the effective average velocity of the entire bottom hole.