Miscible porous media displacements in the quarter five-spot configuration. Part 2. Effect of heterogeneities

摘要: Direct numerical simulations are employed to investigate the coupling between viscous fingering instability and permeability heterogeneities for miscible displacements in quarter five-spot flows. Even moderate inhomogeneities seen have a strong effect on flow, which can result complete bypass of linear growth phase instability. In contrast their homogeneous counterparts (cf. Part 1, Chen & Meiburg 1998), heterogeneous flows exhibit more uniform dominant length scale throughout entire flow domain. line with earlier findings unidirectional displacements, an optimal interaction mobility related vorticity modes occur when is same order as correlation heterogeneities. This resonance mechanism results minimal breakthrough recovery intermediate lengths, at fixed dimensionless rates form Peclet number Pe. However, constant length, does not show minimum Pe varied.Confirming observations, rapid variance variations increases. this tendency far noticeable some parameter regimes than others. It furthermore observed that relatively low variances usually cannot change finger evolve along inherently preferred diagonal direction, especially small lengths. Only higher variances, larger situations off-diagonal become dominant. Due nonlinear nature selection mechanisms work, formation fingers entirely different channels.