Effect of Liquid-Solid Contact Angle on Droplet Evaporation.
Effect of Liquid-Solid Contact Angle on Droplet
Chandra, S.; diMarzo, M.; Qiao, Y. M.; Tartarini, P.
NIST GCR 96-687; Paper 15; June 1996.
Sponsor:National Institute of Standards and Technology,
Available from: National Technical Information Service
Order number: PB96-202304
water sprays; droplets; evaporation; stainless steels;
experiments; computer models; water; hot surfaces; heat
transfer; solid surfaces
The effect of varying initial liquid-solid contact angle
on the evaporation of single droplets of water deposited
on a stainless steel surface is studied using both
experiments and numerical modeling. Contact angle is
controlled in experiments by adding varying amounts of a
surfactant to water. The evolution of contact angle and
liquid-solid contact diameter is measured from a video
record of droplet evaporation. The computer model is
validated by comparison with experimental results.
Reducing contact angle increases contact area between
the droplet and solid surface, and also reduces droplet
thickness, enhancing heat conduction through the
droplet. Both effects increase droplet evaporation
rate. Decreasing the initial contact angle from 90DG to
20DG reduces droplet evaporation time by approximately
50%. The computer model is used to calculate surface
temperature and heat flux variation during droplet
evaporation: reducing contact angle is shown to enhance