English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/108340
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Experiments on microjets of undercooled liquid hydrogen

AutorFernández Sánchez, José María ; Kühnel, Matthias; Tejeda, Guzmán ; Kalinin, Anton; Grisenti, Robert E.; Montero, Salvador
Palabras claveLiquid microjets
Raman spectroscopy
Undercooled hydrogen
Homogeneous solidification
Crystalization kinetics
Fecha de publicación2012
EditorAmerican Institute of Physics
CitaciónAIP Conference Proceedings - American Institute of Physics, 1501 : 1296-1304(2012)
ResumenNovel experiments on liquid microjets (filaments) of hydrogen and deuterium, carried out at the Laboratory of Molecular Fluid Dynamics of the IEM, are reported. These filaments, less than 10 microns in diameter, are an ideal medium to produce highly undercooled liquid samples and to investigate the homogeneous solidification process, free from wall effects. The filaments exit from cryogenic capillary nozzles into a vacuum chamber, to cool down very fast by surface evaporation. Finite size radius leads to a temperature gradient across the filament, determined by thermal conductivity, and, possibly, to a velocity gradient as well. The filaments are monitored by laser shadowgraphy, and analyzed by means of high performance Raman spectroscopy. Real-time measurements in the rotational and vibrational spectral regions reveal the structure and temperature along the filaments, allowing to track the crystal growth process. The high spatial resolution of Raman spectroscopy allows observing in situ the structural changes of the liquid microjets, with a time resolution of ∼ 10 ns. The filaments of pure para-H2 can be cooled down to 9 K (65% of its melting point at 13.8 K), while staying liquid, before eventually solidifying into a metastable polymorph. Crystallization kinetics revealed a growth rate of 33 cm/s, much higher than expected for a thermally activated process. The time and spatial control attained in these experiments offers new opportunities for investigating the processes of nonequilibrium phase transformations in undercooled fluids, as well as the propagation of liquid jets into a rarefied gas media. © 2012 American Institute of Physics
Descripción28th International Symposium on Rarefied Gas Dynamics 2012 (2012). AIP Conf. Proc.; 9 pags. ; 7 figs. ; 1 tab. ; PACS: 67.63.Cd, 33.20.Fb, 64.60.My, 64.70.dg, 47.60.Kz
Versión del editorhttp://dx.doi.org/10.1063/1.4769691
Aparece en las colecciones: (CFMAC-IEM) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
JMFernández.pdf383,26 kBAdobe PDFVista previa
Mostrar el registro completo

Artículos relacionados:

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.