Systematic study of the homogeneity of particle mixtures reveals significant multiscale features in mixing process.In particular,homogenous mixtures at macro-scale may display severe heterogeneity at micro-scale,and vice versa.Meanwhile,different particle sampling methods and mixing indexes may yield significantly varied results for the same mixture at same scales.The results indicate that different mixing indices exhibit inconsistency at different scales.A multiscale mixing index using different methods at appropriate scales and characterizing the homogeneity as a distribution over different scales,rather than a single value at an undefined scale,is hence proposed and considered more precise and comprehensive.
granular systemsmixingmultiscalediscrete element modelingLacey indexrelative standard deviationmacromixingmicromixing