An investigation on the orientation of a long square bar in still water

摘要

An investigation on the orientation of a long square bar in still water was carried out. The inclination angle of the bar is analyzed based on Archimedes' principle and the conditions of the existance of a solution, without apply the transverse metacenter and the principle of minimum potential energy. The correlations between the inclination angle φ and the specific gravity σ of the bar were obtained. And the variation of the water lines of the bar were also obtained. In the rages of σ= (3-{the square roots of 3})/6 to 9/32 and σ= 23/32 to (3+{the square root of 3})/6, the angle φ changes drastically from 0 to 45° and 45 to 0° respectively. Experiments were made for various square bars. The difference between the results and the analysis was explained by the deviation of the center of the gravity of the bar.