Loading...

Three Dimensional Simulation of Morphology of Nanodroplets Near and on Structured Substrates

Vahid, Afshin | 2012

2033 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 43801 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Moosavi, Ali
  7. Abstract:
  8. Mesoscopic hydrodynamic equations are solved employing a VOF based method to investigate the equilibrium shape of nanodroplets positioned over various topographic geometries of the supporting substrate for three-dimensional systems. By taking into account liquid-liquid and liquid-solid interactions a complex distribution for inter-molecular forces over the substrates (the disjoining pressure) is observed. In this research we show that motion of nanodroplets not only caused by contact angle difference in drplets two sides, but also depend on disjoining pressure parameters.Geometries with increasing complexities, from wedges to three dimensional edges and wedges, were explored with the main focus on diverse morphology of droplets in triangular grooves and the stability of the nanodroplets at different positions are studied. In this situations the system containing nanodroplets has it minimum energy and to displace the nanodroplets from this position a considerable driving force is required.Also it is shown that the emergence of certain liquid morphologies in grooves can be actively controlled by changes in wettability and geometry.The effects of dif-ferent parameters such as the profile of the intermolecular interactions and droplet size and the geometry of the topographies are determined and discussed. Finally,we consider in particular the effects of a coating layer on the surface of the substrate because any substrates used in experiments are coated to modify the wetting prop-erties of the substrates
  9. Keywords:
  10. Nanodroplets ; Physical Heterogeneous Substrate ; Modified Volume of Fluid (VOF) ; Three-Dimensional Simulation ; Equilibruim Shape ; Disjoining Pressure

 Digital Object List

 Bookmark