节流器内液-固两相流固体颗粒冲蚀数值模拟

Numerical simulation on solid particle erosion of solid-liquid two-phase fluid in flow controller

建立了考虑颗粒碰撞的颗粒冲蚀计算模型,该数学模型包括:在Eulerian坐标系下求解连续相流场;在Lagrangian坐标系下运用离散颗粒硬球模型求解颗粒碰撞;应用半实验关联式求解颗粒冲蚀速率。对水力加砂压裂施工中节流器内液-固两相流的固体颗粒运动和冲蚀特性进行了数值模拟。计算结果表明,固体颗粒密集于节流器入口到出口的一段狭长区域内,冲蚀速率随流体速度呈指数性变化。颗粒直径越大,冲蚀速率也越大。节流器内冲蚀最严重的位置发生在距离节流器出口上边缘10mm以内的局部区域。

A mathematic model of particle erosion under inter-particle collision was established. This mathematic model includes the flow field simulation of the continuous carrier fluid under Eulerian coordinate system, the inter-particle collision simulation using the discrete particle hard sphere model under Lagrangian coordinate system and the erosion rate calculation using semi-empirical formula- tions. The movement simulation of solid particle and the erosion characteristics of the solid liquid two-phase fluid in flow controller under hydraulic sand fracturing operation showed that the particles were accumulated in a narrow region from inlet to outlet of the flow controller. The erosion rate was proportional to the inlet velocity with the exponential growth. The erosion rate increased with the increase of particle diameter. The most serious erosion in flow controller occurred on the upper region of the edge with 10 mm a way from the outlet.