高压弯管压裂液两相流模拟及流固耦合分析

弯管作为高压管汇的组成部分,发生冲蚀磨损和变形失效情况比直管更加严重,因此对高压管汇弯管部位压裂液固液两相流动及流固耦合效应进行分析具有重要意义。鉴于此,将弯管作为分析对象,采用RANS方法及标准k-ε湍流模型,得到压裂液在弯管中固液两相流压力、速度及颗粒质量浓度分布情况,并通过双向流固耦合技术分析了支撑剂质量浓度、流速及颗粒粒径等因素对弯管剪应力大小及变形的影响。研究结果表明:在弯头部位存在较大的压力和流速梯度,且支撑剂颗粒主要聚集于弯头外侧,该区域存在较大的剪应力和变形;随着支撑剂质量浓度和流速的增加,流固耦合效果越明显,弯管剪应力和变形程度增加,其中流速能显著影响弯管流固耦合程度;随着支撑剂粒径的增大,弯管的流固耦合程度先增大后减小。研究结果可为现场压裂液的设计提供参考。

Numerical Simulation of Two-Phase Flow and Analysis of Fluid-Structure Interaction of Fracturing Fluid in High Pressure Elbow

It is of great significance to analyze the fracturing fluid solid-liquid two-phase flow and the stress and vibration of high-pressure elbow caused by the fluid-structure interaction effects. Taking the high-pressure elbow as the analysis object,the pressure,velocity and particle concentration distribution of the solid-liquid two-phase flow in the high-pressure elbow were obtained based on the Reynolds-Averaged-Navier-Stokes( RANS) equation and the standard k-ε turbulence model. The influences of proppant mass concentration,flow velocity and particle size on the shear stress and deformation of high-pressure elbow were analyzed based on the two-way fluid-structure interaction technology. The research results show that there is a large pressure and flow velocity gradient at the elbow,and proppant particles are mainly gathered in the outer side of the elbow,where there is large shear stress and deformation. As the mass concentration and flow rate of the proppant increase,the fluid-structure interaction effect is more obvious,and the shear stress and deformation of the elbow is larger. The flow velocity can significantly affect the fluid-structure interaction degree of the elbow. As the particle size of the proppant increases,the fluidstructure interaction degree of the elbow increases and then decreases. The study results can provide a reference for fracturing fluid design.