Experimental Investigation of Water Droplet Impingement on a Heated Wax Surface.
Experimental Investigation of Water Droplet Impingement
on a Heated Wax Surface.
(579 K)
Manzello, S. L.; Yang, J. C.
International Journal of Heat and Mass Transfer, Vol.
47, No. 8/9, 1701-1709, April 2004.
Keywords:
droplets; water
Abstract:
The impact of a distilled water droplet upon a heated
wax surface was investigated experimentally using a
high-speed digital camera. The droplet impact Weber
number (We) was varied and the collision dynamics were
investigated with the temperature of the wax surface
varied from 20 to 75 C. For each impact We number, the
evolution of the liquid film diameter was measured as a
function of surface temperature. At We=27, the liquid
film diameter was observed to recoil faster as the
surface temperature of the wax was increased. At We=150,
as the droplet recoiled, an unstable column of fluid was
observed to rise above the wax surface. The instability
of the fluid column at We=150 was explained using
Rayleigh instability theory. At the melting point of the
wax, 75 C, the droplet impacted upon a liquid surface.
Over the range of impact We numbers considered, the jet
formed in the molten wax pool did not result in
separation of droplets from the jet.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899