1954 年 1954 巻 94 号 p. 105-110
Recently in relation to slamming in bad weather, the impact of a body on a water-surface has become important. When a falling body has a keel angle, it is not difficult to estimate the impulsive forces, and this problem has been studied by Pabst, Wagner and others. But in the case of flat plate, it is very difficult to calculate or to measure the pressure on a water-surface. The author investigated theoretically and experimentally this phenomena and obtained the following results.
1. If we assume that the mechanism of the impact of a flat body on a water-surface is the rapid compression of the air-layer caught between body and water-surface, the results of experiments are explained sufficiently.
2. The distribution of impulsive pressure on a flat body is uniform and the pressure in each measured point occurs simultaneously.
3. The relation between impulsive pressure and falling height is not constant but the pressure is proportional to the heigher order of falling height as height becomes higher.
4. Effects of falling mass and diameter of plate are complicated as will be seen in the expressions (24), (26) in this paper.