A surface-tension model was developed for the three-dimensional two-fluid model with interface sharpening algorithm. The two-fluid model contains a pair of momentum equations for each fluid. The newly developed surface tension model splits the surface tension force between both momentum equations. Research is part of the wider international efforts towards the development of three-dimensional two-fluid models, which will overcome the deficiencies of the one-dimensional two-fluid models currently used in nuclear thermal hydraulics.
COBISS.SI-ID: 22549799
The impact of different multiple jet configurations on the heat transfer characteristics and material response to heat loads of the cooling module of a fusion reactor diverter was analysed. It was found out, that optimal configurations from the point of view of heat transfer and stress loading are different. Large Eddy simulations provided novel and important information, which is crucial for the understanding of turbulent flows and validation of simpler and faster models (e.g., RANS), but cannot be directly measured.
COBISS.SI-ID: 24273191
A criterion for the determination of the critical conditions for the hydrodynamic fine fragmentation of partly solidified melt droplets was introduced. Based on the performed experimental analysis, together with the theoretical analysis, the range of the critical conditions for the fine fragmentation of partly solidified droplets was established. The performed analysis for the corium material showed that a crust thickness greater than 20% of the droplet radius can be considered as strong enough to prevent any fine fragmentation during a typical fuel-coolant interaction explosion phase.
COBISS.SI-ID: 27691559
A cohesive element approach to modelling of intergranular cracking on the grain level is presented. It shows that most of the early damage is initiated at intersections of grain boundaries with the external surfaces of the model. A smaller fraction of damage develops inside the model, mostly at the triple lines where several grain boundaries meet. A novelty in this work is the developed analytical expression for assessing the cohesive element response when using viscous regularization for alleviating the convergence issues. The paper contributes significantly to the advancement of the multiscale modelling of the initiation and early growth of short intergranular cracks.
COBISS.SI-ID: 26794279
The implications of the strengthening of the station blackout mitigation capability on the safety of the nuclear power plant are analysed. The assessment is done with the state-of-the-art deterministic and probabilistic methods and tools with applications to the reference models of nuclear power plants. This is the first of a kind demonstration of the applicability of integrated deterministic and probabilistic safety assessment methods to compare safety advantages of different proposal changes following the Fukushima accident in Japan in 2011.
COBISS.SI-ID: 26321959