462 research outputs found

    Effect of the structural parameters changes in the multi-strand tundish on the non-metallic inclusions distribution and separation

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    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

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    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

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    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

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    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

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    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

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    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 āŠ—\otimes 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

    Numeričko modeliranje protjecanja metala u međuloncu sa Å”est žila pomoću različitih uređaja za kontrolu protjecanja

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    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 ā€œtroughā€-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.Numeričko modeliranje Å”iroko se primjenjuje za proučavanje fenomena protjecanja fluida koji se odvija u međuloncu uređaja za kontinuirano lijevanje. U članku su prezentirani rezultati istraživanja protjecanja čelika u međuloncima kapaciteta 22 Mg, s različitim uređajima za kontrolu protjecanja. Međulonac je "koritastog" tipa, a namijenjen je za kontinuirano lijevanje slabova za valjane proizvode malog poprečnog presjeka. Matematičkim proračunima dobije se brzina tekućeg čelika, intenzitet turbulencije, turbulentna kinetička energija i temperaturna raspodjela. Proračuni su provedeni na komercijalnom računalnom programu FLUENT

    Numerical and experimental analysis of vortex sheets behind lifting surfaces

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77273/1/AIAA-1992-409-534.pd

    Numeričko modeliranje protjecanja metala u međuloncu sa Å”est žila pomoću različitih uređaja za kontrolu protjecanja

    Get PDF
    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 ā€œtroughā€-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.Numeričko modeliranje Å”iroko se primjenjuje za proučavanje fenomena protjecanja fluida koji se odvija u međuloncu uređaja za kontinuirano lijevanje. U članku su prezentirani rezultati istraživanja protjecanja čelika u međuloncima kapaciteta 22 Mg, s različitim uređajima za kontrolu protjecanja. Međulonac je "koritastog" tipa, a namijenjen je za kontinuirano lijevanje slabova za valjane proizvode malog poprečnog presjeka. Matematičkim proračunima dobije se brzina tekućeg čelika, intenzitet turbulencije, turbulentna kinetička energija i temperaturna raspodjela. Proračuni su provedeni na komercijalnom računalnom programu FLUENT

    Modeliranje ponaŔanja tijeka taline u razdjelnom loncu Ŕest-žilnog konti-lijeva

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    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.Matematičko se modeliranje intezivno upotrebljava za proučavanje fenomena tijeka tekućina koji se događaju u razdjelnom loncu konti-lijeva. Predstavlja se analiza hidrodinamičkih svojstava realnog industrijskog postrojenja s Å”estožilnim razdjelnim loncem kapaciteta 30 Mg tekućeg čelika. Kao rezultat provedenih numeričkih proračuna, dobivene su prostorne distribucije vektora brzine, polja turbulencijske kinetičke energije, temepratura čelika koji teče u razdjelnik i karakteristika zvana RTD (Residence Time Distribution). Proračuni su provedeni komercijalnim računalskim programom FLUENT. Geometrija i mreža čvorova generirani su programom GAMBIT. Rezultati računalske simulacije provjereni su na industrijskom lijevanju uz upotrebu razdjelnika
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