櫛状格子による液滴の分裂現象

抄録

When a liquid drop strikes vertically upon a linear grid made of equally spaced steel needles, the drop splits into a number of droplets regularly distributed along the direction parallel to the row of needles. If the nature of liquid as well as experimental conditions are not adequate, however, the above mentioned regular splitting does not occur; in some condition, droplets themselves recombine immediately after splitting; in another one, the drop splits into a numerous fine dropletss irregularly scattered. Successive stages of such splitting phenomena are observed by means of instantaneous photography. Water, milk, benzine, ethyl alcohol, methyl alcohol and aqueous solustions of surface-active agent are used. By dimensional analysis, an attempt is made to find the critical condition for the occurrence of regular splitting. Denoting two characteristic numerics by
R=dvρ/η and W=lv²_??_/γ,
where, d: diameter of the grid needle, v: striking velocity, ρ: density of the liquid,
l: diameter of the drop, η: viscosity, γ: surface tension,
we obtain the said critical condition expressed approximately by the relation R·S=Constant, and when the magnitude of this constant in C. G. S. units lies between 1/2·10⁵_??_1/2·10⁶, regular splitting of the drop occurs. Furthermore, by collating to the characteristic features of splitting drop revealed by instantaneous photography, the relation W/R>1 or <1 seems to characterize whether the major factor affecting the phenomenon is viscosity or surface tension.