Abstract:
The scientific goals of this research project focus on enhancement of the physical modelling capabilities and further development of meshless numerical methods for multiphase systems in the presence of electromagnetic and ultrasound fields. The physical modelling of liquid-solid systems will be on the macroscopic scale based on volume-averaged multiphase formulation. The turbulent flow will be treated by large-eddy formulation. The description of free and moving boundaries on the micro and macro-scale will be based on the phase-field concept. This framework will be used to study multiscale solidification and compressible laminar two-phase flow of gas and liquid.
The meshless methods are being developed further due to accuracy, efficiency, simple numerical implementation, similar formulation in two and three dimensions and different possibilities of automatically controlling the quality of the results. The local radial basis function meshless method will be extensively upgraded with new algorithms for pressure-velocity coupling, multi-level iteration solvers, meshless block-structured adaptive node refinement, and meshless specific stabilisation of convection. The non-singular method of fundamental solutions will be further developed for accurate evaluation of Neumann boundary conditions, non-linear material response and moving and free boundary problems.
The mass, momentum, energy and species conservation equations will be simultaneously solved on microscopic and macroscopic levels. The emphasis of the project will be on modularity of the meshless simulation system and on numerical implementation on distributed memory computers. The coupling with artificial intelligence for optimisation and model reduction is foreseen. This will allow many contemporary meshless simulations in global metallurgical and pharmaceutical industry, as well as in large international research centers such as in European XFEL for femtosecond crystallography.
The model assumptions will be experimentally validated based on the predictions of new domestic and foreign laboratory and industrial experiments in the fields of liquid-gas microfluidics and liquid-solid microstructure evolution. The existing comparison exercises for Stefan problems will be complemented with new benchmarks for solidification of multicomponent systems in axisymmetry and three dimensions.
The project is based on further development of our internationally recognised and awarded breakthrough results, achieved in the last few years with meshless methods: the first demonstration of h-adaptive simulations, first solution of engineering turbulence modelling, simulation of magnetohydrodnamics and thermomechanics, large deformations, phase-field modelling of moving and free boundary problems, two-phase flow, solution of a spectrum of most complicated international solidification test cases, and a completely new meshless concept for simulations of mesoscopic microstructure evolution that is based on the point automata instead of the cellular automata. Development of numerous industrial simulation systems, based on this new precompetitive knowledge (continuous casting of aluminium alloys and steel in the presence of electromagnetic fields, thin strip casting, hot rolling, micro-jets, etc.)
The proposed study is expected to gain new, experimentally verified basic knowledge regarding the physical modelling of multiphase systems and a meshless solution of multiscale and multiphysics problems. They will influence further experimental and theoretical developments, design and education. Specific upgrades of the deduced basic knowledge will be used for simulation of various processes in nature and technology. Organisation of an international conference and summer school, dealing with Stefan problems, are scheduled in the framework of the proposed project.
The phases of the project and their realization:
Work Package 1: Refinements of the physical models - realisation of the WP: 40 %
WP1 - Task 1.1: Compressible flow
WP1 - Task 1.2: Advanced nonlinear solid mechanics formulation
WP1 - Task 1.3: External fields (electromagnetic and ultrasound fields)
[1.3.1] MRAMOR, Katarina, VERTNIK, Robert, ŠARLER, Božidar. Application of the local RBF collocation method to natural convection in a 3D cavity influenced by a magnetic field. Engineering analysis with boundary elements. 2020, vol. 116, str. 1-13, ilustr. ISSN 0955-7997.
https://www.sciencedirect.com/science/article/pii/S0955799720300977?via%3Dihub
WP1 - Task 1.4: Multiscale coupling
[1.4.1] ŠARLER, Božidar, DOBRAVEC, Tadej, GLAVAN, Gašper, HATIĆ, Vanja, MAVRIČ, Boštjan,VERTNIK, Robert, CVAHTE, Peter, GREGOR, Filip, JELEN, Marina, PETROVIČ, Marko. Multiphysics and multi-scale meshless simulation system for direct-chill casting of aluminium alloys. Strojniški vestnik. Nov./Dec. 2019, vol. 65, no. 11/12, str. 658-670, ilustr. ISSN 0039- 2480. DOI: 10.5545/sv-jme.2019.6350.[COBISS.SI-ID 3385188].
https://www.sv-jme.eu/sl/article/multi-physics-and-multi-scale-meshless-simulation-system-for-direct-chill-casting-of-aluminium-alloys/
Work Package 2: Advances in meshfree methods - realisation of the WP: 40 %
WP2 - Task 2.1: Novel algorithms for pressure-velocity couplings
[2.2.1] .ZAMOLO, Riccardo, NOBILE, Enrico, ŠARLER, Božidar. Novel multilevel techniques for convergence acceleration in the solution of systems of equations arising from RBF-FD meshless discretizations. Journal of computational physics. 2019, vol. 392, str. 311-334. [COBISS.SI-ID 16607003].
https://www.sciencedirect.com/science/article/pii/S0021999119303171
WP2 - Task 2.2: Multi-level iterative solvers for linear problems
WP2 - Task 2.3: Meshless block-structured adaptive node refinement
WP2 - Task 2.4: Meshless-specific stabilisation of convection
[2.4.1] MAVRIČ, Boštjan, ŠARLER, Božidar. Equivalent-PDE based stabilization of strong-form meshless methods applied to advection-dominated problems. Engineering analysis with boundary elements. 2020, vol. 113, str. 315-327, ilustr. ISSN 0955-7997. DOI: 10.1016/j.enganabound.2020.01.014. [COBISS.SI-ID 17037339], [JCR, SNIP].
https://www.sciencedirect.com/science/article/pii/S0955799720300205?via%3Dihub
WP2 - Task 2.5: Non-singular method of fundamental solutions
[2.5.1] LIU, Qingguo, ŠARLER, Božidar. Method of fundamental solutions without fictitious boundary for three dimensional elasticity problems based on force-balance desingularization. Engineering analysis with boundary elements. 2019, vol. 108, str. 244- 253. DOI: 10.1016/j.enganabound.2019.08.007. [COBISS.SI-ID 1509546].
https://www.sciencedirect.com/science/article/pii/S0955799719305478?via%3Dihub,
[2.5.2] REK, Zlatko, ZAHOOR, Rizwan, ŠARLER, Božidar, Method of regularized sources for potential flow problems, Computers and mathematics with applications.
https://www.sciencedirect.com/science/article/pii/S0898122120302443?via%3Dihub
WP2 - Task 2.6: Parallel implementation
Work Package 3: Artificial intelligence - realisation of the WP: 30 %
WP3 - Task 3.1: Optimisation
WP3 - Task 3.2: Reduced models
[3.2.1] KOVAČIČ, Miha, ŽUPERL, Uroš. Genetic programming in the steelmaking industry. Genetic programming and evolvable machines, ISSN 1389-2576. [Print ed.], Published: 07 February 2020, str. [1-30], doi: 10.1007/s10710-020-09382-5. [COBISS.SI-ID 14436867].
https://link.springer.com/article/10.1007/s10710-020-09382-5
Work Package 4: Experimental methods, verification and validation - realisation of the WP: 35 %
WP4 - Task 4.1: New verification benchmark tests
[4.1.1] HATIĆ, Vanja, CISTERNAS FERNÁNDEZ, Martín, MAVRIČ, Boštjan, ZALOŽNIK, Miha, COMBEAU, Hervé, ŠARLER, Božidar. Simulation of a macrosegregation benchmark in a cylindrical coordinate system with a meshless method. International journal of thermal sciences. Aug. 2019, vol. 142, str. 121-133, ilustr. ISSN 1290-0729. DOI: 10.1016/j.ijthermalsci.2019.04.009. [COBISS.SI-ID 1476266].
https://www.sciencedirect.com/science/article/pii/S1290072918319197?via%3Dihub
WP4 - Task 4.2: Laboratory measurements in Slovenia and Germany
[4.2.1] ZAHOOR, Rizwan, REGVAR, Rok, BAJT, Saša, ŠARLER, Božidar. A numerical study on the influence of liquid properties on gas-focused micro-jets. Progress in computational fluid dynamics. 2020, vol. 20, no. 2, str. 1-13, ilustr. ISSN 1468-4349. DOI: 10.1504/PCFD.2019.10024215. [COBISS.SI-ID 16803867].
https://www.inderscience.com/offer.php?id=106407
[4.2.2] ZAHOOR, Rizwan, KNOŠKA, Juraj, BAJT, Saša, ŠARLER, Božidar, Experimental and numerical investigation of the gas-focused micro-jet velocity. International Journal of Multiphase Flow (poslano v objavo 19. maja 2020).
WP4 - Task 4.3: Industrial measurements in Slovenia and China
