颗粒流钻削润滑中颗粒介质导入的离散相仿真

Discrete phase simulation of the feed-in of lubricating particles during granular flow drilling lubrication

颗粒流润滑是一种高效、绿色固体润滑技术,在切削加工领域已得到初步应用。然而,对于钻削等半封闭加工工艺,有效促进颗粒润滑介质通过钻头与孔壁之间的狭小空隙进入切削区是实现可靠润滑的前提与保障。为探究颗粒介质在钻头和孔壁间隙中的流动特性,促进其有效导入,利用Fluent软件中的离散相模型进行颗粒润滑介质导入的数值仿真。通过不同颗粒介质和钻削参数下的模拟计算,对钻杆与孔壁间隙及内孔壁面的颗粒浓度进行了比较。结果表明,固体颗粒的材质是影响导入量的重要因素,在同一孔深截面处,钻杆与孔壁间隙中的MoS2浓度比石墨浓度更高,且其孔壁黏附量也更大;刀具转速和进给速度的提高有利于润滑颗粒的导入,且转速的作用效果更明显。该研究对于改善颗粒流钻削润滑效果、促进该技术在难加工材料钻削中的应用具有一定的实践价值。

Granular flow lubrication is an efficient and green solid lubrication technology,which has been initially applied in the field of mechanical cutting.However,for semi-closed processing such as drilling,effectively promoting the particle lubrication medium to enter the cutting zone through the narrow gap between the bit and the hole wall is the premise and guarantee of reliable lubrication.In order to explore the flow characteristics of granular medium in the gap between drill and hole wall and promote its effective introduction,the discrete phase model in Fluent software was used to conduct numerical simulation of particle lubrication medium introduction.The gap between drill pipe and hole wall and the particle concentration of inner hole wall are compared by simulation calculation under different particle medium and drilling parameters.The results show that the material of solid particles is an important factor affecting the import amount.The concentration of MoS2 in the gap between drill pipe and hole wall is higher than that of graphite,and the adhesion amount of hole wall is also larger.The increase of tool speed and feed speed is conducive to the introduction of lubricating particles,and the effect of speed is more obvious.This research has certain practical value in improving the lubrication effect of particles media and promoting the application of this technology in the drilling of difficult-to-cutting materials.