A two-dimensional two-scale slice model has been developed to predict the temperature and microstructure evolution in the solidifying strand with the square cross section geometry during continuous casting of steel in company Štore Steel d.o.o.. The enthalpy equation is solved at the macro level by using meshless local radial basis function collocation method (LRBFCM) for spatial discretization and explicit Euler scheme for temporal discretization. The enthalpy, the conductivity and the solid fraction as a function of temperature are calculated by using JMatPro software. The temperature field is interpolated to the micro level by using LRBFCM. At the micro level, the normal distribution and Kurz-Giovanola-Trivedi model are proposed to determine temperature dependent nucleation rate and grain growth velocity, respectively. Meshless point-automata algorithm is applied to implement nucleation and grain growth equations. The model was validated with the experimental data measured in company Štore Steel d.o.o..
F.09 Development of a new technological process or technology
COBISS.SI-ID: 513016177The simulation system involves coupled simulation of solid mechanics, fluid mechanics, electromagnetic fields and microstructure in DC casting of Al alloys. The system is based on our original meshless solution procedures. It is in industrial use in IMPOL Slovenska Bistrica company.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 3868948Meshless methods represent a very fast developing field of computational mechanics. Their main distinction from classical numerical methods, such as finite element, finite volume or boundary element method is that their trial functions depend only on node arrangement, without building any geometrical objects between the nodes. This approach gives many advantages with respect to the classical methods, such as high order of smoothness, no mesh distortion problems, etc. They also perform surprisingly well in the strong form formulation, which has an additional advantage of no need for integration. They turned out to be particularly advantageous in moving boundary and inverse problems. An overview of meshless methods based on collocation with radial basis functions for multiphysics and multiscale problems will be given. Specific accent on computational fluid dynamics issues such as adaptivity, upwinding and pressure- velocity coupling will be elaborated in detail, concluded by several examples from modelling of continuous casting of steel and aluminium alloys, on micro and macro-scales, to modelling of hot rolling of steel.
B.04 Guest lecture
COBISS.SI-ID: 4019195A 3D multiphysics simulation of continuous casting of steel with mold electromagnetic stirring is presented for Štore Steel continuous caster. The electromagnetic force is calculated with a finite element method, whereas the molten steel flow and solidification is calculated with a local radial basis function collocation meshless method (LRBFCM). Electromagnetic stirring causes rotational flow, which amplifies cooling and promotes solidification. These results are similar to other publications in the field. However, since stirring parameters are not optimal, defects occur. Although LRBFCM has already been applied to a 3D problem of continuous casting of steel, this is the first time the calculation also includes the electromagnetic stirring.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 1336746Reason: Prof. Šarler developed a new, conceptually simple, meshless numerical approach for treatment of partial differential equations based on radial basis functions with local support, and use it to accurately and efficiently solve numerous natural and technical problems with many unknowns. They encompass multiphase and multiscale systems influenced by electromagnetic fields coupled with nonlinear solid and turbulent fluid mechanics. His main contribution is an original general numerical method, with qualities such as no need for mesh and local integration, simple numerical implementation, adaptivity and usefulness for complex geometries in multiple dimensions. Together with his co-workers he applied the method to systems design in large foreign research centers and for domestic and foreign metallurgical industry. He published the mentioned research in 30 notable articles in leading world scientific journals in the field of development and application of numerical methods. He also received multiple international awards and served as an invited lecturer at several international conferences, universities, and institutes.
E.01 National awards