Drilling process of indexable drill bit based on Coupled Eulerian-Lagrangian method:A simulation study

42CrMo steel has the characteristics of high strength,high wear resistance,high impact resistance,and fatigue resistance.Therefore,drilling 42CrMo steel has always been a challenging task.The indexable drill bit has the advantages of high processing efficiency and low processing cost and has been widely used in the field of aerospace hole processing.To better understand the machining mechanism of the indexable drill bit,this paper uses the Coupled EulerianLagrangian method(CEL)to simulate the three-dimensional drilling model for the first time.The simulation results of the drilling force obtained by the CEL method and Lagrangian method are compared with the experimental results.It is verified that the CEL method is easy to converge and can avoid the problem of program interruption caused by mesh distortion,and the CEL simulation value is more consistent with the actual value.Secondly,the simulation results of cutting force and blade cutting edge node temperature under different process parameters are extracted.The variation of time domain cutting force,frequency domain cutting force and tool temperature with process parameters are obtained.This study provides a new method for the prediction of cutting performance and the optimization of process parameters of indexable drills.

基于欧拉-拉格朗日分裂法的供水管网多组分水质模拟

供水管网中的水质模型通常为对流反应方程,往往忽略扩散项。在水质模型中加入扩散项,并探讨了水质模拟中扩散效应的影响。采用一种适用于供水管网的欧拉-拉格朗日分裂算子法求解多组分(有机质、余氯和微生物量)传质反应模型的对流扩散反应方程组,并应用于动态水力条件下的算例管网中。实例证明,下游节点的污染物浓度随时间逐渐积累增加,尤其在管网终端扩散效应显著。相比有机质和余氯的浓度变化,轴向扩散效应和径向传质反应效应相互促进的综合效应使得微生物量显著变化,低流速情况下表现更为明显。