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Experimental Investigation of Water Droplet Impingement on a Heated Wax Surface.


pdf icon 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.