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Autori: L. Vekas, M.I. Piso, D. Bica, I. Potencz
Editorial: European Space Agency, ESA Publications Division, Microgravity Research and applications in Physical Sciences and Biotechnology, SP-454, p.183, 2000.
Two types of complex magnetizable media are considered in this work: a) magnetic liquids (ferrofluids) with deformable nonmagnetic inclusions (gas bubbles) and b) magnetic liquids with solid inclusions in the micrometer range. In both cases the behaviour of these composite fluid systems is strongly influenced by an applied magnetic field, but also by gravitational forces (e.g. lifting the bubbles and producing the sedimentation of heavier solid particles in the magnetic liquid). Theoretical modeling of the media, together with laboratory experiments, conducted to results for both cases. For gas bubbles, the dependence of the bubble frequency and volume on the applied magnetic field has been determined. For solid inclusions, an effect of microscopic rotation in the fluid has been observed. Both effects could become significant for technology applications, in particular in controlled thermal transfer and active media for sensors. The purpose of this work is to suggest scientific experiments onboard a space orbital laboratory. It is expected that the effects would be more significant due to the microgravity conditions, which offer the natural environment for the research and applications of complex magnetizable fluids
Cuvinte cheie: microgravity, complex fluids, nucleate boiling, nanostructures