462 research outputs found
Effect of the structural parameters changes in the multi-strand tundish on the non-metallic inclusions distribution and separation
The aim of presented studies was to investigate the fluid flow change and non-metallic inclusions removal changes due to tundish construction modifications. In presented study, numerical simulations were used. Numerical simulations are carried out with the finite-volume commercial code ANSYS Fluent. Steady-state casting conditions for the flow structure and the inclusions removal process are analysed
Analysis of liquid steel flow in a multi-strand tundish using numerical methods
The article presents the results of liquid steel flow and mixing in tundish when applying turbulence inhibitor to modernize the tundish working zone. The flow of six-strand continuous casting tundish of a trough-type was investigated with numerical modeling. For turbulence modeling, the Reynolds-Averaged Navier-Stokes (RANS) equation and the Large Eddy Simulation (LES) methods have been used. Numerical simulations are carried out with the finitevolume commercial code AnsysFluent
Validation of numerical model of a liquid flow in a tundish by laboratory measurements
The article presents results of physical and numerical modelling of steel flow through a tundish of continuous casting machine. In numerical calculations the influence of mesh density was tested and the correctness of the flow description in the near-wall region was checked using Standard Wall Function model. Obtained results were verified using experimental results of velocity field (PIV method) coming from a water tundish model
Non-metallic inclusions controling at the ladle furnace (LF) station
The article contains the results of research performed on the determination of the quantity and morphology of nonmetallic inclusions identified at the secondary metallurgy process during the cold-swelling steel production. Continuous improvement of steel quality standards, which today is primarily associated with the amount of inclusions contained in the steel product, enforces actions taken to remove the largest possible number of inclusions from steel and/or by their modification at the final stage of secondary metallurgy processing. Therefore, research was undertaken at the ladle furnace industrial stand, and the steel samples were subjected to metallographic testing. It was shown that the number and/or the size of inclusions identified in the samples taken at the beginning and end of the process decreased, and in addition they were modified
Depression and religiosity in older age
We investigated the hypothesis that religious commitment could help counter general affective distress, accompanying depressive symptoms, in older age. A total of 34 older adults, all catholic believers, completed self-reported questionnaires on the presence of depressive symptoms, religiosity, health, worry, and the style of coping with stress. The depressive and non-depressive subgroups were then created. The prevalence of depressive symptoms was 50%, with the substantial predominance of females. Regression analyses indicate that health expectations and worry significantly worsen with increasing intensity of depressive symptoms. The results further show that religious engagement was not different between the depressive and non-depressive subgroups. Religiosity failed to influence the intensity of depressive symptoms or the strategy of coping with stress in either subgroup, although a trend was noted for better health expectations with increasing religious engagement in depressive subjects. We conclude that religiosity is unlikely to significantly ameliorate dysphoric distress accompanying older age
Differential Algebras in Non-Commutative Geometry
We discuss the differential algebras used in Connes' approach to Yang-Mills
theories with spontaneous symmetry breaking. These differential algebras
generated by algebras of the form functions matrix are shown to be
skew tensorproducts of differential forms with a specific matrix algebra. For
that we derive a general formula for differential algebras based on tensor
products of algebras. The result is used to characterize differential algebras
which appear in models with one symmetry breaking scale.Comment: 21 page
NumeriÄko modeliranje protjecanja metala u meÄuloncu sa Å”est žila pomoÄu razliÄitih ureÄaja za kontrolu protjecanja
Numerical modelling have been extensively used to study the fluid flow phenomena taking place in continuous casting tundish. The paper presents the results of steel flow researches done on tundishs with a capacity of 22 Mg, with different flow control devices. The tundish is a ātroughā-type designed for the continuous casting of slabs intended for small cross-section rolled products. In effect of mathematical calculations liquid steel velocity, turbulence intensity, turbulent kinetic energy and temperature distributions have been obtained. Calculations were passed by commercial computer program FLUENT.NumeriÄko modeliranje Å”iroko se primjenjuje za prouÄavanje fenomena protjecanja fluida koji se odvija u meÄuloncu ureÄaja za kontinuirano lijevanje. U Älanku su prezentirani rezultati istraživanja protjecanja Äelika u meÄuloncima kapaciteta 22 Mg, s razliÄitim ureÄajima za kontrolu protjecanja. MeÄulonac je "koritastog" tipa, a namijenjen je za kontinuirano lijevanje slabova za valjane proizvode malog popreÄnog presjeka. MatematiÄkim proraÄunima dobije se brzina tekuÄeg Äelika, intenzitet turbulencije, turbulentna kinetiÄka energija i temperaturna raspodjela. ProraÄuni su provedeni na komercijalnom raÄunalnom programu FLUENT
Numerical and experimental analysis of vortex sheets behind lifting surfaces
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77273/1/AIAA-1992-409-534.pd
NumeriÄko modeliranje protjecanja metala u meÄuloncu sa Å”est žila pomoÄu razliÄitih ureÄaja za kontrolu protjecanja
Numerical modelling have been extensively used to study the fluid flow phenomena taking place in continuous casting tundish. The paper presents the results of steel flow researches done on tundishs with a capacity of 22 Mg, with different flow control devices. The tundish is a ātroughā-type designed for the continuous casting of slabs intended for small cross-section rolled products. In effect of mathematical calculations liquid steel velocity, turbulence intensity, turbulent kinetic energy and temperature distributions have been obtained. Calculations were passed by commercial computer program FLUENT.NumeriÄko modeliranje Å”iroko se primjenjuje za prouÄavanje fenomena protjecanja fluida koji se odvija u meÄuloncu ureÄaja za kontinuirano lijevanje. U Älanku su prezentirani rezultati istraživanja protjecanja Äelika u meÄuloncima kapaciteta 22 Mg, s razliÄitim ureÄajima za kontrolu protjecanja. MeÄulonac je "koritastog" tipa, a namijenjen je za kontinuirano lijevanje slabova za valjane proizvode malog popreÄnog presjeka. MatematiÄkim proraÄunima dobije se brzina tekuÄeg Äelika, intenzitet turbulencije, turbulentna kinetiÄka energija i temperaturna raspodjela. ProraÄuni su provedeni na komercijalnom raÄunalnom programu FLUENT
Modeliranje ponaŔanja tijeka taline u razdjelnom loncu Ŕest-žilnog konti-lijeva
Mathematical modeling has been extensively used to study the fluid flow phenomena taking place in continuous casting tundish. The article presents an analysis of the hydrodynamic properties of a real industrial facility ā a six-strand tundish of a capacity of 30 Mg liquid steel. As a result of numerical computations carried out, spatial distributions of the velocity vectors, fields of turbulence kinetic energy, temperature of steel flowing in the tundish and characteristics called RTD (Residence Time Distribution) were get. Calculations were carried out by commercial computer program FLUENT. The geometry and nodal point grid were generated in the GAMBIT program. Results of computer simulation were verificated on the industrial tundish.MatematiÄko se modeliranje intezivno upotrebljava za prouÄavanje fenomena tijeka tekuÄina koji se dogaÄaju u razdjelnom loncu konti-lijeva. Predstavlja se analiza hidrodinamiÄkih svojstava realnog industrijskog postrojenja s Å”estožilnim razdjelnim loncem kapaciteta 30 Mg tekuÄeg Äelika. Kao rezultat provedenih numeriÄkih proraÄuna, dobivene su prostorne distribucije vektora brzine, polja turbulencijske kinetiÄke energije, temepratura Äelika koji teÄe u razdjelnik i karakteristika zvana RTD (Residence Time Distribution). ProraÄuni su provedeni komercijalnim raÄunalskim programom FLUENT. Geometrija i mreža Ävorova generirani su programom GAMBIT. Rezultati raÄunalske simulacije provjereni su na industrijskom lijevanju uz upotrebu razdjelnika
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