低圧気体中で接近する2球間に作用する抗力

概要

論文の詳細を見る
In a continuum, the resistance force of a spherical particle moving towards another particle increases with decreasing separation distance between particles and finally becomes infinite just before touching. However, there has been no investigation on the effect of discontinuity. The air in the minimum separation of two particles whose diameters are less than several tens of microns creates the discontinuum, and without it, a fine particle would collide with another particle more easily. In this study, we measured the resistance force of a 6.3 mm foam styrene ball under reduced pressure by using a high-speed camera. At 10 Pa, the mean free path of air is 670μm and the Knudsen number of a 6.3 mm foam styrene ball is equivalent to that of a 0.6μm particle in air. The experimental data show that the increment of the resistance force acting on a 6.3 mm foam styrene ball near the spherical particle under reduced pressure decreases with decreasing air pressure. Hence, it is concluded that the resistance force of a fine particle moving towards another particle in the air is much less than that acting in a continuum.
一般社団法人日本機械学会の論文
1994-06-25