For the purpose of studying mechanisms of drop formation along with the varieties of the mean diameters of the drops formed, benzene was injected at o velocity of 1-150cm/sec. through a nozzle (with diameters ranging as shown in Table 2) into water or other aqueous solutions with different physical properties (Table 1).
The behaviours of the jet of benzene, including drop formation, were studied and the mean diameters of the drops formed were measured by meansof photographs taken with the help of an electric flash (time, about 2×10^-4sec).
The drop-formation processes were classified into four patterns according to the change in the velocity of benzene injected, the critical points thereof being, u_j, u_k, u_s, where,
u_j stands for a velocity at which a benzene column comes into view,
u_k stands for a velocity at which a benzene column is at its maximum height,
u_s stands for a velocity at which very fine droplets come to be formed.
The first pattern covers injections at a speed lower than u_j, where drops are formed separately, the second one, injections at a speed of u_j-u_k, where drops are formed at the farther end of the benzene column owing to the laminar flow (Fig.1, d-f), the third one, injections at a speed of u_k-u_s, where the jet length decreases and is bent at its top, presumably due to the turbulent flow (Fig.1, g-i) and the fourth one, injections at a speed higher than u_s, where the jet is deformed and cut into very fine droplets. These critical points may be presented as follows:
The minimum value of d (defined in Eq. (6)) coincides with that of the theoretical diameter, proving that the jet is disintegrated in the wave length of oscillation along the column owing to the maximum instability, and that drops are formed of this disintegrated jet.