ESR 12

Multiphase flow modelling with upscaling using continuum approaches

Multiphase flow modelling with upscaling using continuum approaches

In this research project, the focus is on poly-disperse, dense fluid-solid flows which are ubiquitous in nature and industry.

In fluid-solid flows, a wide range of length and time scales exist and hence the need for various modelling approaches at different scales. For this reason, numerical simulations on different scales, from micro- to meso- to macroscale, will be conducted.

The notion of carrying out simulations at a variety of scales is based on using information on the smallest scale  (microscale) to construct adequate models on larger scales (meso- and macroscale) by up-scaling techniques.

As a start, simulations on mesoscale of fluidised beds have been performed. For instance, the presented figure shows a mesoscale simulation of the fluidisation of a bi-disperse particle bed. Such simulations are necessary for evaluation of developed models. The simulation results can be compared to existing experimental work on fluidised beds and it can be shown that the physical phenomena, such as segregation, are properly described.

The project aim in a nutshell:

Obtaining high fidelity data from microscale simulations which resolve all scales in poly-disperse, dense fluid-solid flows and hence are usable to construct new models on larger scales (meso-macro).

Tim Najuch


I studied mechanical engineering at the Karlsruhe Institute for Technology in Germany. During my studies, I specialised in fluid mechanics and computational fluid mechanics. Fortunately, I had the opportunity to gain practical insight into various interesting research fields, such as CFD optimisation techniques, magnetohydrodynamics and multiphase flow. The latter experience astonished me by its enormous complexity and has made me curious to work in the field of multiphase flow modelling.

Contact details


Tim Najuch