截断式脉冲水射流冲蚀煤岩特性数值模拟

Numerical simulation of coal rock fragmentation characteristics under interrupted pulse water jet

基于光滑粒子动力学和有限元法(smoothed particle hydrodynamics-finite element method,SPH-FEM)耦合算法,建立了截断式脉冲水射流冲蚀煤岩的数值计算模型。通过对比数值模拟结果与相同工况下的实验结果,验证了该模型的有效性。在此基础上,探究了在截断式脉冲水射流冲击作用下,煤岩沿射流轴向的损伤演化过程,分析了煤岩围压、脉冲长度、脉冲间距及射流速度对煤岩冲蚀深度及速度的影响规律。结果表明:煤岩的冲蚀深度随着围压增大而减小;随着脉冲长度的增加,煤岩的冲蚀深度逐渐减小,冲蚀速度经历了先增大后减小的过程;脉冲间距对冲蚀深度的影响较小,煤岩的冲蚀速度随脉冲间距的增大呈现出线性减小的变化趋势;脉冲速度对冲蚀深度及速度影响较为显著,且随着脉冲速度的增加,冲蚀深度及速度整体呈增长趋势。

Based on a coupling algorithm of smoothed particle hydrodynamics(SPH)and finite element method(FEM),a numerical calculation model for the erosion of coal rock by an interrupted pulse water jet was established.The feasibility of the model was verified by comparing the results of the numerical simulation with the experimental results under the same working conditions.Based on this,the axial damage evolution process of coal rock under the impact of truncated pulse water jet was explored,and the influences of coal rock confining pressure,pulse length,pulse spacing and jet velocity on the coal rock erosion depth and speed were analyzed.The results show that the greater the confining pressure of coal rock,the smaller the erosion depth and the slower the erosion speed.As a result,with the increase of pulse length,the erosion depth gradually decreases,and the erosion speed will successively undergo growth phase and reduction phase.The pulse interval has little effect on the erosion depth,and the erosion speed decreases linearly with the increase of the pulse interval.The pulse velocity has a significant effect on the erosion depth and speed,and as the pulse velocity increases,the erosion depth and speed generally increase.