Anomalous heat transport by the piston effect in supercritical fluids under zero gravity
1990; American Physical Society; Volume: 41; Issue: 4 Linguagem: Inglês
10.1103/physreva.41.2264
ISSN1538-4446
AutoresBernard Zappoli, Didier Bailly, Yves Garrabos, B. Le Neindre, P. Guénoun, D. Beysens,
Tópico(s)Nanofluid Flow and Heat Transfer
ResumoThe response to a boundary heating of a very compressible, low-diffusivity, supercritical fluid (${\mathrm{CO}}_{2}$) under zero-gravity is studied by solving numerically the full non-linear one-dimensional Navier-Stokes equations. Both short (acoustic) and long (diffusion) time scales are investigated. A new mechanism of heat transport is seen, where the thermal energy is transformed into kinetic energy in a hot expanding boundary layer (the piston), which in turn is transformed in the bulk into internal energy. Steeply profiled waves are observed. In contrast to the ``critical slowing down'' behavior, the enhancement of heat transport is so important that it is nearly completed after 1% of the diffusion time.
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