THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

online first only

Study of transient condensation occurring during the starting of the evaporation of a droplet deposited on a heated substrate

ABSTRACT
The evaporation of a drop deposited on a heated substrate is a complex process, which combines several phenomena such as the Marangoni effect, mass and thermal transfers, etc. We developed, in this paper, a mathematical model and a numerical simulation code used to carry out an in-depth study about the evaporation of a drop deposited on a heated substrate surrounded by air. This numerical study was supported by experimental work. The numerical findings obtained showed the existence of a condensation phenomenon for certain configurations. At the beginning of the experiment, the evaporation started at the triple point. However, a local region of the interface remained relatively cold. In this region, the concentration gradient (Cv, Csat) directed from the liquid-gas interface to the air resulted in condensation of water steam. Although this phenomenon is temporary and visible only at the start of evaporation process, its study makes it possible to better understand and optimize the evaporation kinetics.
KEYWORDS
PAPER SUBMITTED: 2018-11-22
PAPER REVISED: 2019-08-29
PAPER ACCEPTED: 2019-09-06
PUBLISHED ONLINE: 2019-10-06
DOI REFERENCE: https://doi.org/10.2298/TSCI181122377K
REFERENCES
  1. Wang, W. et al., Scanning force microscopy of DNA molecules elongated by convective fluid flow in an evaporating droplet, Biophysical Journal, 75 (1998), 75, 513-520.
  2. Saito, M. et al., Evaporation and combustion of a single fuel droplet in acoustic fields. Fuel, 73 (1994), 349−353.
  3. Murko, V. I. et al., Investigation of the spraying mechanism and combustion of the suspended coal fuel, J. Thermal Science, 19, (2015), 243-251.
  4. Chen, Z. et al. Numerical simulation of single-nozzle large scale spray cooling on drum wall, J. Thermal Science 22, (2018), 359-370.
  5. Khilifi, D. et al. Study of the phenomenon of the interaction between sessile drops during evaporation, J. Thermal Science, 23, (2019), 1105-1114.
  6. Chandra, S. et al., Effect of liquid-solid contact angle on droplet evaporation, Fire safety journal, 27(1996), 141-158.
  7. Mollaret, R. et al., Experimental and numerical investigation of the evaporation into air of a drop on a heated surface, Chem. Eng. Res. Des. 82 (2004), 471-480.
  8. Widjaja, E., Harris, M. T., Numerical study of vapor phase diffusion driven sessile drop evaporation, Computers and chemical Engineering, 32 (2008), 2169-2178.
  9. Strotos, G. et al., Numerical investigation on the evaporation of droplets depositing on heated surfaces at low weber numbers, International journal of heat and mass transfer, 51 (2008) 1516-1529.
  10. Ait Saada, M. et al., Evaporation of a sessile drop with pinned or receding contact line on a substrate with different thermophysical properties, International journal of heat and mass transfer, 58 (2013) 197-208.
  11. Semenov, S. et al., Evaporation of sessile water droplets: Universal behaviour in presence of contact angle hysteresis, Colloids and Surfaces A: Physicochem. Eng. Aspects, 391 (2011) 135-144.
  12. Lu, G., Internal flow in evaporating droplet on heated solid surface, International journal of heat and mass transfer 54 (2011), 4437-4447.
  13. Ait Saada, M., Numerical investigation of heated an mass transfer of an evaporating sessile drop on a horizontal surface, Phys.Fluid 22 (2010), 112-115.
  14. Lopes, M. C. et al., influence of the substrate thermal properties on sessile droplet evaporation: Effect of transient heat transport, Colloids and surfaces A: Physiocochem.Eng.Aspects, 432 (2013). 64-70.
  15. Yang, K. et al., A fully coupled numerical simulation of sessile droplet evaporation using Arbitrary Lagrangian-Eulerian formulation, International journal heat and mass transfer 70 (2014) 409-420.
  16. Diddens, C. et al., Modeling the evaporation of sessile multi-component droplets, Journal of Colloid and Interface Science, 487 (2017), 426-436.
  17. Ben Jabrallah, S., Convective heat and mass transfer with evaporation of a falling film in a cavity. International Journal of Thermal Sciences 45 (2006), 16-28.