ISSN Online: 2377-424X
International Heat Transfer Conference 12
On the heat and mass tranfer with liquid-vapor phase change in capillary porous media. Application to capillary evaporators
要約
Two aspects of transfers within the wick of a capillary evaporator are considered. First, we discuss experimental
results obtained with a transparent two-dimensional porous medium. On the whole, the results are in agreement
with previous pore-network numerical simulations. However, the experimental results also indicate the existence
of thin films along the pore walls that explains why trapped liquid clusters can be observed even under steady-state
conditions. This effect was neglected in the simulations. Then, we address the problem of the growth of the
vapor zone induced by the imposed heat load at the boundary of the porous domain. We develop theoretical
arguments and simulations consistent with the existence of a lower operating limit. The analysis suggests that the
heat load should be sufficient for viscous effects to affect significantly the extension of the vapor zone in order to
prevent possible depriming of the system due to a capillary fingering breakthrough.