Polydisperse multiphase systems are constituted by particles/bubbles/droplets suspended in a continuous phase. The simulation of their evolution is complicated by the numerous time- and length-scales involved and one promising approach consists in coupling together two or more modelling methods, focusing in turn on one of the relevant scales: namely macro-scale, population-scale, particle/bubble/droplet-scale and the underlying molecular-scale. The different modelling methods can be based on classical continuum mechanics (e.g. Navier-Stokes equations) and account for the existence of a population of particles/droplets/bubbles (e.g. Boltzmann/population-balance equation) or can be based on the atomistic and molecular description (e.g. full-atom or coarse-grained molecular dynamics). Different coupling strategies are employed: often the macro-scale and the population-scale are coupled on-the-fly by using Quadrature-Based Moment Methods (QBMM), whereas coupling with the particle/bubble/droplet-scale or with the molecular-scale is realized off-line by using the parameter passing (or surrogate model) approach.

In this seminar three different examples will be discussed: (1) coalescence, breakage and mass transfer in liquid-liquid and gas-liquid dispersions, (2) polymer molecule self-assembly and polymer foam expansion and (3) particle transport, deposition and aggregation in porous media. In the first example the use of this methodology for the simulation of gas-liquid bubble columns and stirred tank reactors will be presented. Particular emphasis will be placed on the type of population-scale model (mono- or bi-variate) to be used to properly simulate the process. The second example refers to the production of polymer nanoparticles for controlled drug delivery applications and the production of polyurethane foams for mould filling applications. In this second example particular attention will be placed on the coupling between macro-scale and molecular-scale models. In the last example the discussion will focus on the use of these technique to simulate different porous media, from catalytic chemical reactors to particle filters and aquifers.

Bio-sketch:
Daniele Marchisio graduated in Chemical Engineering in 1997 from Politecnico di Torino (Italy) and obtained his PhD from the same institution in 2001 (with a stay at Iowa State University as visiting scholar). After a post-doc at Iowa State University (2001-2003) and a short permanence as visiting guest at ETH Zurich (2004) he became assistant professor at Politecnico di Torino (2004), where he was then promoted to associate (2010) and full professor (2016). He has also been visiting professor at University College London (summers of 2007 and 2008), visiting scientist at CSIRO Melbourne (2013) and he currently is Adjunct Visiting Professor at the Beijing University of Chemical Technology (2016-2019). He is an active member of different professional organizations (AIDIC, GRICU, AIChE, EFCE, APS) including the working parties on multiphase flow and industrial crystallization of the EFCE and of several scientific committees. He has co-authored a book on computational models for multiphase flows (for Cambridge Univ. Press) and more than 100 papers published on international journals.