Modelling of aggregate restructuring in a weakly turbulent flow

Abstract

To cite this version:Frédéric Gruy.Modelling of aggregate restructuring in a weakly turbulent flow. AbstractAn aggregate may undergo a restructuring that leads to a change of its porosity. The cause of this morphology change is not only the colloidal forces between the primary particles but also the interaction between the primary particles and the flowing fluid. We investigate in this paper the restructuring of the aggregates with Van der Waals forces between the primary particles in the presence of the Brownian motion and a weakly turbulent flow. The motion of all the primary particles constituting the aggregate is studied thanks to a 1-D model based on the work of G. Narsimhan [Model for drop coalescence in a locally isotropic turbulent flow field, J. of Colloid & Interface Science, 272(2004)197-209]. A shrinking rate law, i.e. aggregate porosity versus time, is proposed after a transition to a 3-D model. Its characteristic time depends on the initial porosity, the number of primary particle and a characteristic time at the scale of the primary particle.

Aggregation of growing crystals in suspension: I. Mumtaz revisited

“…Mumtaz's work has found applications in industrial crystallisation (Braun et al, 2004;Brunsteiner et al, 2005;Chen et al, 2004;Chen et al, 2003;Chew et al, 2004;Falk et al, 2011;Hollander et al, 2003;Ilievski, 2001;Ilievski and Livk, 2006;Kramer and Jansens, 2003;Li et al, 2001;Livk and Ilievski, 2007;Rielly and Marquis, 2001;Wang et al, 2006;Yokota et al, 1999;Zauner and Jones, 2000), precipitation (Lakshminarayanan and Valiyaveettil, 2003;Lewis and Mangere, 2011;Lindenberg et al, 2008;Lawler, 2008, 2010;Wagterveld et al, 2012;Wan et al, 2011), nanoprecipitation (Jia et al, 2008;Pujol et al, 2004;Schwarzer and Peukert, 2005;Schwarzer et al, 2006), population balance modelling (Balakin et al, 2012;Briesen, 2006;Briesen, 2007;Derksen, 2002;Hollander et al, 2001a;Hollander et al, 2002;Hollander et al, 2001b;Mersmann et al, 2002;Reinhold and Briesen, 2012;Sgraja et al, 2010) and colloid science (Gruy, 2012;Kind, 2002).…”

Collision rate constant for non-spherical particles moving under shear flow

“…Collision between aggregates has to take account of their permeability as well [17,18]. However, the comparison between these simulations and experiments suggests that internal mechanisms as restructuring, sintering between primary particles and fragmentation occur [19][20][21][22][23][24][25][26]. The resulting aggregates are more compact and elongated.…”