基于折射率匹配实验图像指标的含液颗粒物质系统内部固体体积分数重构  

Reconstruction of the internal volume fraction for particle-liquid system from imaging indicators by refractive index matching

作　　者：孙云辉 焦佳珺 安翼 王晓亮 刘青泉 Yunhui Sun;Jiajun Jiao;Yi An;Xiaoliang Wang;Qingquan Liu(School of Aerospace Engineering,Beijing Institute of Technology,Beijing,100081,China;Key Laboratory for Mechanics in Fluid Solid Coupling Systems,Institute of Mechanics,Chinese Academy of Sciences,Beijing,100190,China)

机构地区：[1]School of Aerospace Engineering,Beijing Institute of Technology,Beijing,100081,China [2]Key Laboratory for Mechanics in Fluid Solid Coupling Systems,Institute of Mechanics,Chinese Academy of Sciences,Beijing,100190,China

出　　处：《Acta Mechanica Sinica》2024年第2期39-53,共15页力学学报（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.12032005 and 12172057)。

摘　　要：折射率匹配技术被广泛用于研究颗粒-液体混合流动,但是目前针对其固体体积分数的确定为经验性的且缺乏理论或实验支撑.为了合理确定内部体积分数,本文开展了系统的标定实验来研究固体体积分数和图像指标的关系.结果表明基于面积分数的模型由于颗粒表观尺寸的不稳定性,会产生较大的误差,传统使用的正比例模型仅在靠近标定点附近的体积分数成立.本文提出了基于Voronoi多边形等效直径的预测模型,结果表明该模型更为准确且稳定,该模型被进一步应用于颗粒-液体斜槽流动中以研究内部体积分数剖面和底部应力.Refractive index matching(RIM)is widely used to investigate particle-liquid mixture flows.However,determining the volume fractionφin RIM is generally empirical and lacks theoretical or experimental basis.To reasonably reconstruct the internalφ,this study performs systematic calibration experiments to study the relationship betweenφand the imaging indicators.The results show that the model based on area fraction c2D will induce a large error for lowφowing to the instability of the particle’s apparent size.The traditionally adopted proportional functionφ=ac2D is only valid forφnear the calibration point.A predictive model is proposed based on the size of the Voronoi cell,dpoly,which proves to be more accurate and stable in RIM experiments.The dpoly-based model is applied to dense granular flows down an inclined plane to study the internal profiles ofφand the bottom normal stress.

关 键 词：Voronoi多边形 折射率匹配 颗粒物质 等效直径 标定点 比例模型 标定实验 实验图像 

分 类 号：O3[理学—力学]