Scaling impact crater dimensions in cohesive rock by numerical modeling and laboratory experiments

Author(s):  
N. Güldemeister ◽  
K. Wünnemann ◽  
M.H. Poelchau
2020 ◽  
Vol 117 (5) ◽  
pp. 509
Author(s):  
Marcin Bielnicki ◽  
Jan Jowsa

The paper presents results of physical and numerical modeling of liquid slag entrainment during continuous casting of steel slabs process. The main aim of this work was to determine the critical casting speed and also to specify, which entrainment mechanism is most responsible for transport of slag droplets into steel volume. Physical modeling was based on water-oil model of mould, made on reduced linear scale of Sl = 0.4. In mathematical modeling, Realizable k-ε and LES WALE models were used to describe turbulent motion of water and oil, whereas Volume of Fluid model was used to take into account interactions between phases. It was found, that the main cause of slag entrainment is the formation of von Karman vortex in the vicinity of submerged entry nozzle. The results of laboratory experiments and numerical simulations were compared each other. Both method are a useful tools for modeling of slag entrainment. Great agreement was found between laboratory experiments and numerical simulation carried out using LES WALE model, regarding the shape of the oil and oil entrainment as a result of vortex structures formation. However, in the simulation case using Realizable k-ε model, the oil entrainment hasn’t been modeled for the conditions under consideration.


Author(s):  
Sungwon Shin ◽  
Kideok Do ◽  
Daniel Cox

Coastal sand dunes are important in the nearshore environment with respect to the sand supply, ecosystem, and hazard mitigation. While the reliable prediction of the dune erosion is important, numerical modeling of this phenomenon is still challenging. In this study, a process based morphological modeling was performed and the results were compared with large-scale laboratory experimental data.


2017 ◽  
Vol 25 (03) ◽  
pp. 1750023 ◽  
Author(s):  
Nathalie Favretto-Cristini ◽  
Arkady M. Aizenberg ◽  
Bjørn Ursin ◽  
Paul Cristini ◽  
Anastasiya Tantsereva

The Discretized Kirchhoff Integral method has been recently tested against laboratory experiments using a model with surface curvatures and sharp edges generating wave diffraction effects. Comparisons between numerical and laboratory data have exhibited a good quantitative fit in terms of time arrivals and amplitudes, except in the vicinity of secondary shadow boundaries created by the interaction of the edges of some topographical structures. Following this work, the effect of multiple scattering and the surface curvatures on the wavefield is studied here, using the so-called diffraction attenuation coefficient, in order to define the cases where these effects may be neglected in the numerical modeling without loss of accuracy.


Sign in / Sign up

Export Citation Format

Share Document