DOI: 10.1615/ICHMT.2014.IntSympConvHeatMassTransf
ISBN Print: 978-1-56700-356-7
ISSN Online: 2642-3499
ISSN Flash Drive: 2642-3502
CFD CALCULATION OF EVAPORATION RATE WITH ACCOUNT FOR VOLUME CONDENSATION
SINOPSIS
Evaporation rate is directly calculated by performing CFD simulations of concentration- and temperature-induced convection in air with saturated vapor boundary condition specified at the liquid-air interface. The results in terms of Sherwood-Rayleigh relationship are compared to known empirical expressions. It is shown that empirical correlations in dimensional form are valid only for water reservoirs with the same size as in the original experiments. In contrast, nondimensional correlations exhibit good agreement with simulation results for moderate Rayleigh numbers in the well-explored case of liquid hotter than the ambient air. Thermodynamical model for the effect of the volume condensation upon Sherwood and Nusselt numbers is constructed. For the limiting case of fast condensation it can be used to calculate evaporation rate even with CFD codes, which do not support simulation of vapor transport. Also, a remarkable difference is experimentally discovered of temperature fields over liquid surface and solid heater with the same temperature, indicating the influence of condensation heating. This can provide data for verification of CFD models involving volume condensation.