Collision dynamics of a water droplet impinging on a hot solid surface

The collision dynamics of a water droplet impacting on a solid surface heat ed above the Leidenfrost temperature are treated in this paper. Emphasis is placed upon the droplet disintegration process and the effects of the Reyn olds number, as well as the solid surface temperature, on the droplet defor mation process. As a result, it has been found that, for the case of low We ber number, but above the critical one, the droplet breaks up into some par ts in the recoiling process and that as the Weber number is increased furth er, the droplet disintegration occurs in a spreading process. It has been c onfirmed that the effect of the Reynolds-number on the droplet deformation is negligibly small in the earlier stage, but a little significant in the l ater stage just before/after rebounding from the surface. Furthermore, it has been clarified that there is almost no effect of the su rface temperature, or the Reynolds number, on the maximum spreading diamete r, the time needed for the spreading droplet to reach a maximum diameter, a nd the time from the moment of collision to rebounding from the surface.