Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1029/2021WR029861
Licence creative commons licence
Title (Primary) Impact of surface roughness on evaporation in 2D micromodels
Author Ding, Y.; Geistlinger, H.
Source Titel Water Resources Research
Year 2021
Department BOSYS
Volume 57
Issue 11
Page From e2021WR029861
Language englisch
Topic T5 Future Landscapes
Keywords Capillary flow visualization; 2D micromodel evaporation; Surface roughness; Wettability; Fractal evaporation front
Abstract Evaporation - a key process for water exchange between soil and atmosphere - is controlled by internal water fluxes and surface vapor fluxes. Recent studies demonstrated that the dynamics of the water flow in pore corners and thick-film flow on the rough pore-solid interface determine the time behavior of the evaporation rate. A comprehensive experimental study of the combined effect of corner flow (CF) and thick-film flow (TFF) on evaporation is lacking. Herein, we present a comparative micromodel study of the evaporation process using 2D-porous media, which exhibit the same stochastic pore structure, but different degree of surface roughness (silicon micromodels with smooth surface; glass-ceramic micromodels with rough surface). Our study proves both experimentally and theoretically that surface roughness and wettability play a key role for the time- and temperature behavior of the evaporation process. We found a similar urn:x-wiley:00431397:media:wrcr25614:wrcr25614-math-0001-behavior up to 42°C regarding the mass loss as function of time in stage-2 and a transition to linear t-behavior for higher temperatures (61°C), with high statistical significance (regression coefficients near 1) for both micromodels. Our experimental results elucidate the strong temporal correlation between mass loss and geometric pattern of the unsaturated CF and TFF region. Partial wetting in silicon micromodels causes a weak driving force for CF, whereas complete wetting in glass-ceramic micromodels causes a strong driving force for TFF. For a consistent description of the time-dependent mass loss and geometry of the CF/TFF region, the fractality of the evaporation front must be considered. Based on our data we estimate the film-thickness and discover some interesting film thinning effect with increasing temperature.
Persistent UFZ Identifier
Ding, Y., Geistlinger, H. (2021):
Impact of surface roughness on evaporation in 2D micromodels
Water Resour. Res. 57 (11), e2021WR029861 10.1029/2021WR029861