A new semi-empirical correlation for estimating settling dynamics of suspensions in viscoelastic shear-thinning fluids

Abstract

The optimization of sedimentation and hydrotransport systems involving settling suspensions in viscoelastic fluids has been hindered by a lack of robust and scalable mathematical models that accurately characterize settling dynamics in such scenarios. This study aimed to enhance understanding of this problem by developing a semi-empirical correlation that is dependent on space and time. This correlation describes batch settling characteristics during the ‘acceleration phase’ of settling, including changes in settling velocity and solids concentration of suspensions in a viscoelastic shear-thinning fluid under quiescent conditions.A novel dimensionless ratio- the ‘particle-acceleration’ number- was developed to simulate time-dependent settling velocities. The correlation’s accuracy was confirmed through validation which involved predicting two key parameters- the duration of the acceleration settling phase (with 86–98% accuracy) and the final solids concentration at the sample depth once the acceleration phase ended (with 82–96% accuracy).