2021-12-01

Jan Boháček finished his habilitation and became associate professor this month. Jan Boháček operates in the field of heat transfer. Mainly, he focuses on CFD simulations. His habilitation is called ‘Simulation and Modeling of Horizontal Centrifugal Casting’.

The habilitation thesis is a logical outcome of Boháček’s research activities at the Chair of Simulation and Modeling of Metallurgical Processes at Montanuniversitaet Leoben between the years 2010 and 2020. Funded by the Austrian COMET Competence Centre Programme (K2) and the industry partner, Eisenwerk Sulzau-Werfen, R. & E.

When 3D Volume of Fluid models prepared in ANSYS FLUENT turned out to be computationally very expensive, the idea about modifying shallow water equations (SWE) emerged. A trick of solving SWE by using the Euler-Euler model was applied. Despite having a comprehensive model of horizontal centrifugal casting, several drawbacks were identified, which eventually led to the development of a more accurate and much faster approximate Riemann solver. The main advantage was that a 3D scenario about spreading the liquid metal along with a gradually solidifying shell could be captured in a fair amount of time. However, some missing parts of physics and a certain pressure by the industry partner resulted in the development of a 2D free-surface model based on the full Navier-Stokes equations, which was eventually incorporated into a user-friendly graphical interface.

Boháček developed a friendly-user graphical user interface in MATLAB. Example of imposing the initial and boundary conditions. 

The code was further extended to consider a shrinkage of the solidifying shell. The numerical model is able to capture various wave patterns on the free-surface that interacts with the solidifying liquid metal. The numerical model amply demonstrates the oscillating trajectory of an equiaxed crystal carried by the melt. The numerical can simulate the whole horizontal centrifugal casting process including pouring the outer (first) layer as well as the intermediate (second) layer until solidification is finished.

Congratulations to associate professor Jan Boháček!