抄録
The behavior of interface between a water droplet dyed red to make dear its boundary and silicone oil surface on which the droplet falls was observed by using a high speed video recorder with 500 frames per second. Eleven kinds of silicone oil whose kinetic viscosity νT is 1 mm2/s to 105 mm2/s were used as the target liquid A droplet having 3.1 mm diameter falls freely from a micropipet whose height was varied between 100 mm and 1000 mm.
The configuration of silicone oil cavity at its deepest state and that of deformed droplet at its maximum spread were classified into seven and five respectively based on their observation results. Under some conditions disintegration of droplet were observed, which accompanied remarkable deformation of oil surface at lower viscosity νT<102 mm2/s, while it occurred on the plane oil surface at higher viscosity of νT>5×103 mm2/s.
