抄録
Deformations of a water droplet impinged on the hot metal surfaces were studied. Thin film flow at the bottom part of the deformed droplet was regarded as a potential flow and theoretical velocity components and pressure distributions in it were given. The droplet is decelerated by the pressure difference at the bottom and the upper surfaces.
From mass and energy balances of the thin film flow theoretical relations of the film thickness and the radial extent of the thin film flow were derived and compared with the experimental data which had been obtained from measurements on the photographs presented by WACHTERS et al.
For an initial impacting velocity of v0=63 cm/s, the theory on the film thickness and the radial extent well coincided with the experimental data both in the cases taking no account of the surface tension of the droplet and taking account of it. When v0 is 139 cm/s, the radial extents theoretically predicted with taking account of the surface tension only at the spherical portion of the droplet coincide with the data. In the similar calculations under conditions of v0=220 cm/s it was found that the coincidences were within about 25%.
