Detachment of inclined spheroidal particles from flat substrates

Abstract

The detachment of fine particles attached to a solid substrate or rock surface significantly affects colloidal transport in porous media. The work is devoted to quantifying the detachment conditions for inclined oblate spheroids subjected to creeping viscous flow. A numerical and a laboratory study were conducted to systematically evaluate the impact of the orientation (pitch) angle towards the hydrodynamic moment, adhesive DLVO force, contact area, and critical detachment velocity. The methodology developed to produce stretched latex polystyrene particles reduces the geometric uncertainty of nonspherical fines. The geometry of the produced oblate spheroids is fully determined by the semi-major and semi-minor axes. For inclined attached particles, an explicit formula has been derived for the detaching velocity, where the detaching drag torque exceeds the attaching adhesion torque. The probabilistic distribution of the model parameters for the detachment velocity of the inclined particles attached to the plane substrate provides upscaling for fines detachment from the particle to porous media scale.