Exact moment analysis of transient dispersion properties in periodic media

摘要: This paper develops a homogenization approach, based on the introduction of exact local and integral moments, to investigate temporal evolution effective dispersion properties point-sized finite-sized particles in periodic media. The proposed method represents robust computationally efficient continuous alternative stochastic dynamic simulations. As case study, moment is applied analyze transient sinusoidal tubes under action pressure-driven Stokes flow. structure tube wall induces significant variation axial velocity component along coordinate. strongly influences behavior V z(t) dispersivity Dz(t), both exhibiting wide persistent oscillations, even for steady (not-pulsating) For pointwise injection solute symmetry axis, many interesting features appear: negative values coefficient Dz(t) larger than asymptotic value Dz(∞), anomalous scaling variance particle distribution. All these peculiar found physical theoretical explanation by adopting simple transport models accounting radial field its interaction with molecular diffusion.This many...