TY - JOUR
T1 - Physics of Fluid Spreading on Rough Surfaces
AU - Hay , K. M.
AU - Dragila , M. I.
JO - International Journal of Numerical Analysis and Modeling
VL - 5
SP - 85
EP - 92
PY - 2018
DA - 2018/11
SN - 5
DO - http://doi.org/
UR - https://global-sci.org/intro/article_detail/ijnam/841.html
KW - roughness, wetting, capillarity
AB - <p style="text-align: justify;">In the vadose zone, fluids, which can transport contaminants,
move within unsaturated rock fractures. Surface roughness has not been
adequately accounted for in modeling movement of fluid in these complex
systems. Many applications would benefit from an understanding of the
physical mechanism behind fluid movement on rough surfaces. Presented
are the results of theoretical investigation of the effect of surface
roughness on fluid spreading. The model presented classifies the regimes
of spreading that occur when fluid encounters a rough surface: i)
microscopic precursor film, ii) mesoscopic invasion of roughness and
iii) macroscopic reaction to external forces. Theoretical diffusion-type
laws based on capillarity and fluid and surface frictional resistive
forces developed using different roughness shape approximations are
compared to available fluid rise on roughness experiments. The
theoretical diffusion-type laws are found to be the same apparent
functional dependence on time; methods that account for roughness shape
better explain the data as they account for more surface friction.</p>