论文和技术资料

A robust and computationally efficient homogenization approach, grounded on exact local and integral moments, is proposed to investigate the temporal evolution and asymptotic properties of the effective velocity vector and the dispersion tensor in Hydrodynamic Chromatographic Columns (HDC) as well as in Liquid Chromatography (LC), in which diffusion and adsorption/desorption processes occur in the micro-porous stationary phase. The time-dependent coupled transport equations for the local moments and the stationary equations for the b-fields can be efficiently implemented and solved in Comsol (Coefficient Form PDE). Suppose the hierarchical porous media can be represented as the periodic repetition of an n-dimensional unit lattice cell. In that case, the transient analysis requires the solution of the time-dependent advection-diffusion equations for the zeroth-order and first-order exact local moments, exclusively on the unit cell, where periodic boundary conditions are enforced. This implies an enormous reduction of the computational efforts and a significant improvement in the accuracy of the results when compared to direct numerical simulation (DNS) approaches.