摘要
水力压裂中,裂缝壁面对支撑剂团在狭窄裂缝中输送沉降时的受力有重要影响。该文基于LBM建立颗粒流动数值模型,构建星型、三棱柱型、长方体型颗粒团簇模型,研究颗粒团簇在不同雷诺数Re、颗粒团簇与壁面相对距离H/d下的升阻力变化规律。结果表明:壁面影响下,随Re的增大,颗粒团簇的曳力系数、升力系数均减小,且壁面方向升力系数总小于无壁面方向的结果;单颗粒曳力系数与团簇平均曳力系数的比值随Re的增加而减小,随壁面边界效应的影响而增大;不同位置的颗粒曳力系数比值表现为前排颗粒减小、中间颗粒先增大后减小、近壁面颗粒逐渐增大。随H/d的增大,颗粒团簇远离壁面,边界影响减弱,曳力系数减小程度逐渐减弱;前排及近壁面颗粒曳力系数比值与升力系数随之减小;远壁面颗粒逐渐靠近壁面,曳力系数比值增大。壁面边界效应会加剧近壁面颗粒受力,且外侧颗粒对内部颗粒受力有屏蔽作用。
In hydraulic fracturing,the fracture wall has an important influence on the force of proppant clusters when transporting and settling in narrow fractures.In this study,a numerical model of particle flow is established based on the lattice Boltzmann method.The star,triangular prism and cuboid particle cluster models are constructed to study the variation of lift and drag of particle clusters under different Re and relative distance H/d from the wall.The results show that the drag and lift coefficients of particle clusters decrease with Re under the influence of wall,and the lift coefficient in the wall direction is always smaller than that in the non-wall direction.The ratio of single particle drag coefficient to cluster average drag coefficient decreases with Re,and increases with the influence of wall boundary effect.For the drag coefficient ratio of particles at different positions,it decreases for the front row particles,and it increases first and then decreases for the middle particles,and it gradually increases for the particles near the wall.With the increase of H/d,the particle clusters are far away from the wall and the boundary influence is weak,and the decrease rate of drag coefficient decreases gradually.For the front row particles and particles near the wall,the ratio of drag coefficient and lift coefficient decrease.The particles away from the wall gradually approach the wall,and the ratio of drag coefficient increases.The wall boundary effect can aggravate the force on the particles near the wall,and the outer particles have a shielding effect on the forces on the inner particles.
作者
张涛
吴春燕
孙堃
卢聪
李聪
ZHANG Tao;WU Chun-yan;SUN Kun;LU Cong;LI Cong(Petroleum Engineering School,Southwest Petroleum University,Chengdu 610000,China;State Key Laboratory of Aerodynamics,Mianyang 621000,China)
出处
《工程力学》
EI
CSCD
北大核心
2024年第3期241-249,共9页
Engineering Mechanics
基金
国家自然科学基金项目(52022087)。
关键词
LBM
颗粒团簇
曳力系数
升力系数
壁面效应
水力裂缝
LBM
particle clusters
drag coefficient
lift coefficient
wall effect
hydraulic fracture
