Search results for "stirring"
showing 6 items of 6 documents
Influence on the macrosegregation of binary metallic alloys by thermoelectromagnetic convection and electromagnetic stirring combination
2014
International audience; Influence of a slowly rotating 0.5 T transverse magnetic field on the directionally solidified metallic alloy has been experimentally studied in this work. Main idea is to study an influence on the melt flow and material structure caused by the simultaneous electromagnetic stirring and thermoelectromagnetic convection with comparable magnitudes. Electromagnetic stirring and thermoelectromagnetic convection intensities have been estimated analytically to find optimal experimental parameters. It is experimentally demonstrated that with such an interaction it is possible to modify component macrosegregation of Sn-10 wt% Pb alloy. Helical macrosegregation within cylindri…
Experimental investigation of low-frequency pulsed Lorentz force influence on the motion of Galinstan melt
2016
Abstract The paper presents the results of the numerical and physical experiments, aimed at assessing the influence of pulsed force of electromagnetic field on the melt motion and the fluid velocities. The experiment was performed on the eutectic alloy Galinstan in the cylindrical volume, where an ultrasonic Doppler velocimeter was employed for velocity measurements under conditions of pulsed and steady EM field application. A numerical simulation of the melt flow, forced by the steady EM force, involved a 2D axisymmetric model. The k-e turbulence model was used to obtain the information about the melt velocities. The verification of the numerical model was carried out for the steady case. …
Numerical and experimental study of liquid metal stirring by rotating permanent magnets
2018
In this work, we study liquid gallium stirring by rotating permanent magnets. We demonstrate possibility of easily creating different flow patterns by rotating permanent magnets, which can be industrially important for controlling heat and mass transfer processes in the system. Unlike the typical approach of simulating magnet rotation as a transient problem and time-averaging the Lorentz forces, we solve the magnet rotation as a harmonic (frequency domain) problem, which leads to forces equal to time-averaged ones and decreases the simulation time considerably. Numerical results are validated using qualitative flow structure results from the neutron radiography visualization of tracer parti…
Tailoring the microstructure and mechanical properties of Ti–Al alloy using a novel electromagnetic stirring method
2006
The effect of melt convection during the solidification of Ti45Al55 alloys was investigated in terms of microstructure evolution and the resulting mechanical properties. The samples were subjected to conventional induction melting as well as enhanced melt stirring by an external magnetic field using a specially designed floating zone arrangement. The stirred samples showed a significant improvement of plastic deformability. A strong change in the morphology from dendritic to spherical and an increased properitectic phase fraction were observed after stirring.
Les colloïdes solubles du vin de champagne. Relation avec le « remuage »
1978
<p style="text-align: justify;">Dans ce travail on étudie un échantillonnage de vins de champagne, en vue d'établir une relation entre leur composition en colloïdes et la facilité du « remuage ».</p><p style="text-align: justify;">Après champagnisation, les teneurs en colloïdes totaux sont toujours supérieures à celles des vins tranquilles correspondants. Plus la durée de clarification et de remuage est grande plus la teneur en colloïdes est élevée.</p><p style="text-align: justify;">Le fractionnement des colloïdes glucidiques solubles, en quatre fractions, sur Sépharose 6 B montre que celle de plus haut poids moléculaire a l'influence la plus directe sur les d…
Prévenir et réduire les risques de sélection de résistances : de la théorie à la pratique, des pistes pour améliorer la durabilité des PPP
2015
SPEPôle GEAPSICT2communication orale invitée, résumé; La résistance est le résultat inéluctable de la sélection exercée par les PPP sur les populations de bio-agresseurs. On ne peut pas empêcher une résistance d’évoluer, mais on peut retarder substantiellement son évolution en mettant en place des stratégies appropriées avant (prévention) et après (gestion) la détection des premiers individus résistants. Le point-clef à retenir pour cela est que plus le contrôle d’un bio-agresseur est basé sur une chimie peu diversifiée, plus le risque de sélectionner rapidement une résistance est élevé. Un exemple type de ce qu’il ne faut pas faire est de contrôler un bio-agresseur présent sur de grandes s…