群粒子の見掛け干渉終速度におよぼす管径の影響
1982 年 98 巻 1128 号 p. 93-98
詳細
1982 年 98 巻 1128 号 p. 93-98
Apparent terminal velocity, U, of a cloud of spheres with narrow size distribution was measured in fluidized bed and the effect of pipe wall on the velocity was evaluated by including d/D term in the following equations,
_??_
where Uo=terminal settling velocity of a single sphere in an infinite fluid, C=volume fraction of particles, Φ=CiRe/24, Ci=inertial drag coefficient for a single sphere, Re=Reynolds number for a single sphere, d, D=particle and pipe diameter respectively.
According to the equation above, the effect of d/D on terminal velocities varied with particle Reynolds number and Concentration.
However, considering a size ratio of particle to pipe diameter and particle Reynolds number in a practical hydraulic transportation, the effect of d/D was reduced to a simple term as 1-d/D.
Based on this result and the simplification of the other terms, the equation for a rough estimation was derived as follows.
