半球形突起弯管冲蚀特性数值研究  

Numerical Analysis of the Erosion Characteristics of Hemispherical Protrusion Elbow

作　　者：李睿[1] 孙治谦[1] 李安俊[1] 王森[1] 王振波[1] LI Rui;SUN Zhi-qian;LI An-jun;WANG Sen;WANG Zhen-bo(New Energy College,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)新能源学院,山东青岛266580

出　　处：《表面技术》2021年第9期215-224,共10页Surface Technology

基　　金：国家自然科学基金(51774314)。

摘　　要：目的设计一种带有半球形突起的表面结构,以减轻弯管在气固两相流中受到的冲蚀,并对其冲蚀分布和内部的流场结构进行分析。方法采用CFD-DPM方法,将气相作为连续相,颗粒作为离散相,结合双向耦合、RNG k-ε湍流模型、Finnie冲蚀预测模型、Grant颗粒反弹模型和粗糙度模型进行计算,将试验数据与计算结果进行对比,以此验证计算的精确性。结果标准弯管中,冲蚀主要发生的部位为外壁θ=50°至θ=65°,最大冲蚀速率为4.40×10^(-4)kg/(m^(2)·s)。对于表面突起的弯管,当突起位置θ=30°时,最大冲蚀速率达到最低,为2.82×10^(-4)kg/(m^(2)·s);当突起位置θ=75°时,最大冲蚀速率达到最大值,为6.61×10^(-4)kg/(m^(2)·s);突起上的最大冲蚀速率在θ=60°时达到最大,为4.99×10^(-4)kg/(m^(2)·s),其他位置突起的最大冲蚀速率均低于3.5×10^(-4)kg/(m^(2)·s),但平均冲蚀速率较高。结论在弯管表面的特定位置设置半球形突起,可以改变颗粒轨迹,降低二次流影响,并在其下游形成缓冲涡,从而对壁面起到保护作用。尤其是当突起位置θ=30°、半径r=D/7时最为明显,最大冲蚀速率相较标准弯管降低了37.05%。但随着突起位置的靠后,其保护作用也逐渐衰弱。A surface structure with hemispherical protrusions is designed to reduce the erosion of the elbow in the gas-solid two-phase flow,and its erosion distribution and internal flow field structure are analyzed.According to the CFD-DPM method,the gas phase is used as the continuous phase and the particles are as the discrete phase.The calculation is carried out by combining the two-way coupling,RNG k-εturbulence model,Finnie erosion prediction model,Grant particle rebound model and roughness model.The calculation results are compared to verify the accuracy of the calculation.In standard elbows,the main location where erosion occurs is the outer wallθ=50°toθ=65°,and the maximum erosion rate is 4.56×10^(-4)kg/(m^(2)·s).For curved pipes with protrusions on the surface,when the protrusion positionθ=30°,the maximum erosion rate reaches the lowest,which is 2.82×10^(-4)kg/(m^(2)·s);when the protrusion positionθ=75°,the maximum erosion rate of the maximum rate is 6.61×10^(-4)kg/(m^(2)·s);the maximum erosion rate on the protrusion is 4.99×10^(-4)kg/(m^(2)·s)atθ=60°.The maximum erosion rates of protrusions in other locations are lower than 3.5×10^(-4)kg/(m^(2)·s),but the average erosion rate is higher.Setting a hemispherical protrusion at a specific position on the surface of the elbow can change the particle trajectory,reduce the influence of the secondary flow,and form a buffer vortex downstream of it,thereby protecting the wall.Especially when the protrusion position isθ=30°and the radius r=D/7,the maximum erosion rate will be reduced by 37.05%compared with the standard elbow.But as the position of the protrusion moves back,its protective effect gradually will be weaken.

关 键 词：气固两相流 弯管 冲蚀 新结构 数值模拟 

分 类 号：TH117.1[机械工程—机械设计及理论] O359[理学—流体力学]