液中を落下する球の初期速度に関する実験的知見

抄録

Experimental studies were made to evaluate the drag forces on an accelerated sphere falling in liquid in gravitational field.
From the data we obtained:
1) With increase of Acceleration modulus Ac (=v²/d_Pv), drag force due to acceleration v, that is due to virtual mass, tends to be neglected.
2) In the region, that is in a distance from start point having a length same order of magnitude as that of diameter d_P, drag force on a sphere due to acceleration markedly effects the movement of sphere.
3) With the assumption that, drag force could be estimated with the usual drag coefficient defined by stational relative velocity, trajectory of falling sphere may be evaluated when A_C>1.