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Experimental Study of a Water Droplet Impinging on a Liquid Surface.


pdf icon Experimental Study of a Water Droplet Impinging on a Liquid Surface. (329 K)
Manzello, S. L.; Yang, J. C.

Experiments in Fluids, Vol. 32, No. 5, 2002.

Keywords:

droplets; water; liquid surfaces; thermophysical properties; surface tension; impingement

Abstract:

An experimental study is presented for water droplet impingement on a liquid surface. The impaction process was recorded using a high-speed digital camera at 1000 frames per second. The initial droplet diameter was fixed at 3.1 mm 0.1 mm and all experiments were performed in atmospheric air. The impact velocity was varied from 0.36 m/s-2.2 m/s thus varying the impact Weber number from 5.5-206. The impacted liquid surface consisted of two fluids, namely water and methoxy-nonafluorobutane, C4F9OCH3 (HFE7100). The depth of the water and HFE-7100 pool was varied from 2 mm to 25 mm. The collision dynamics of water in the HFE-7100 pool was observed to be drastically different than that observed for the water droplet impingement on a water pool. The critical impact Weber number for jet breakup was found to be independent of liquid depth. Water-HFE7100 impact resulted in no jet breakup over the range of velocities studied. Therefore, no critical impact Weber number can be defined for water-HFE7100 impact.