【摘要】 针对旋冲钻孔过程存在孔底岩屑堵塞的问题，基于气固两相流理论，考虑岩屑颗粒碰撞对气力排屑特性的影响，建立了环形流道内岩屑碰撞接触受力模型及气力排屑环形流道模型，采用计算流体力学-离散单元法（CFD-DEM）模拟垂直环形流道内气力排屑过程，得到了气流速度、排屑气压与岩屑粒径对气力排屑特性的影响规律。结果显示：随着气流速度的增大，流场压力损失先减少后增加，存在最佳排屑气流速度18m/s，当低于该速度时，岩屑难以及时排出；排屑压力减小导致环形流道中心区域岩屑浓度上升，导致压降增加；岩屑粒径小于1mm容易集聚成带状流动，当岩屑粒径在（2～4）mm范围内时，利于岩屑的排出。为岩石钻具的钻孔及排屑工艺参数选择提供了依据。更多还原

【Abstract】 Aiming at the problem of blockage at the bottom of vertical rotary drilling,based on the theory of gas-solid two-phase flow,considering the influence of debris collision on the characteristics of pneumatic chip removal. the model of rock debris collision contact force and the pneumatic chip evacuation annular flow channel model in the annular flow channel are established.The pneumatic chip removal process in the vertical annular flow channel was simulated with the computational fluid dynamicsdiscrete element method(CFD-DEM),and the influence of airflow velocity,chip evacuation pressure and cuttings particle size on the pneumatic chip removal characteristics were obtained. The results indicate that the pressure loss of the flow field decreases first and then increases and there is the best airflow velocity with the increase of airflow velocity. There is an optimum airflow rate of 18m/s,and when it is lower than this speed,the cuttings are difficult to discharge in time. The reduction of the chip discharge pressure leads to the increase of the cuttings concentration in the central region of the annular flow channel,and the pressure drop is increases.The cuttings with a particle size of less than 1mm tends to accumulate into a strip flow. When the particle size of cuttings is within the range of(2～4)mm,it is conducive to the discharge of cuttings. It provides a basis for the selection of drilling parameters and chip removal process parameters of rock drilling tools.更多还原