缩径管内两相流砂粒碰撞和冲蚀特性研究

针对目前建模方法在描述两相流中砂粒碰撞行为方面存在的不足，运用计算流体力学和离散单元耦合方法建立了压裂工况下的缩径管两相流模型，实验验证了仿真模型的准确性。分析了缩径管内砂粒间碰撞及缩径斜面受力规律，研究发现，缩径斜面冲蚀深度随砂比增大而增大，砂比大于40%时，相同时间的冲蚀深度增量减小，并趋于最大值；缩径斜面冲蚀深度随黏度增大而减小，流体黏度对缩径斜面外缘比对内缘的冲蚀深度影响大。

Study on Sand Collisions and Erosion Characteristics of Two Phase Flow in Contraction Pipes

As the shortcomings of current modeling method in describing the sand erosions in two phase flow, CFD-DEM was used to build contraction pipe two phase flow in fracturing condition, the accuracy of simulation model was testified by experiments and the force laws of particle collisions and contraction areas in contraction pipes were analyzed. The results show that the erosion depth of contraction areas increases by sand ratios, and the erosion depth increment decreases and approaches the maximum during the same period when the sand ratio is over 40%. The erosion depth of contraction area decreases with the viscosity increments and the influences of fluid viscosity on contraction area outer margin are bigger than inner edge.