Jure Ravnik of University of Maribor, Maribor, Slovenia

In this tutorial, we will examine the study and practical importance of particle-laden flows ranging
from dilute suspensions of spherical rigid droplets to inhomogeneous soft deformable particles. Particulate
systems are widely used in various industries such as cement, petrochemical, wastewater treatment, and
pharmaceutical, where different types of particles are transported, mixed, stored, or segregated. In addition,
nonspherical particles are widely present in nature, from the composition of blood to dust particles in the air.
On the other hand, not all particles are rigid nor are they homogenous. Research in the field of soft deformable
particles is less established. Nevertheless, there are relevant examples of suspensions, both of industrial and
scientific interest, where the suspension consists of soft, non-linearly deformable micron- and submicron-
sized particles that have a non-spherical shape due to the deformability of the particles. These particles
include microgels, filled polymers, biological cells, as well as liquid droplets, vesicles and liquid capsules, with
elastic or viscoelastic properties. To model or control systems which include these soft, deformable particles,
the governing physics of the particle system must be well understood. We will showcase how by simulating
airflow patterns using computational fluid dynamics (CFD), we can model how droplets containing pathogens
are dispersed during human activities such as breathing or coughing. These simulations provide insights into
the physical mechanisms involved and help assess infection risks. CFD tools also enable the evaluation of
short-term, short-range flow dynamics, aiding in the prediction of droplet dispersion patterns. We will stress
the importance of accurate modeling, as it informs strategies to mitigate disease spread. For instance,
improving air quality management can reduce exposure to pathogen-laden particles, thereby lowering
infection risks. Additionally, understanding the dynamics of particle motion helps identify key factors
influencing transmission, such as droplet size, velocity, and trajectory.
Beyond the specific case of COVID-19, these we will present the broader implications of particle-laden flows
in various environmental and industrial applications by focusing on non-spherical, inhomogeneous and
deformable particles and showcase the integration of advanced computational tools with physical modeling
as a powerful approach to addressing complex flow problems.

Biography:

Jure Ravnik is a professor of Power, Process, and Environmental
Engineering at the University of Maribor’s Faculty of Mechanical Engineering in
Slovenia. His research interests span multiphase and multicomponent fluid flows,
turbulence, heat and matter transfer, numerical methods, and approximation
methods. He has been involved in various research and development projects at
national and EU levels, including the simulation of fluid flows during paper
production, nanofluid behavior, and the development of numerical algorithms for
diverse applications. Furthermore, Dr. Ravnik actively participates in commissions,
societies, and associations, organizes conferences and edits journals, contributing
significantly to the academic and research community in the field of transport
phenomena modelling. Currently, he serves as the Head of the Laboratory for transport phenomena in solids
and fluids and the Head of Academic Assembly of the Faculty of Mechanical Engineering, University of
Maribor.

Address:University of Maribor, , Maribor, Slovenia, Slovenia