1980 年 96 巻 1104 号 p. 80-84
In this paper a one-dimensional fully established annular flow analysis on a drag coefficient could be developed and compared with the results of the boundary layer theory as described in the previous paper and with experimental results for various factors of capsules which were freely suspended in a vertical tube with water.
The drag coefficient could be shown as follows:
_??_
l;length/diameter ratio of capsule
Re;Reynolds number Um d/v
Um;superficial mean flow veiocity to freely-Suspended capsule
v;kinematic viscosity of the fluld
d;capsule/pipe diameter ratio
ddiameter of capsule
It was apparent that the drag coefficient charagteristics curve obtained from the above equatlon could be apPilcable for the range of characteristics number l/(1/d-1) 2Re<0.01.