A Study of Motion of a Sphere in Air Flow through Horizontal Pipe

Abstract

The present study was carried out to obtain basic data for the numerical simulation of pneumatic transport of solid particles. In the equation of motion of a spinning sphere, a force F^^→_v due to the velocity gradient of air flow through pipe was newly proposed. In the preliminary experiment, the drag coefficient C_d, coefficient of restitution e, friction coefficient μ_d were measured. Their values were substituted into the corresponding terms of the equation of motion. The equation of motion was numerically soved by the Runge-Kutta-Gill method. The values of lift coefficient C_L and coefficient G_s for F^^→_v were decided by making comparison between the computed and experimental results of the trajectory of sphere. As a result, C_d=0.6, G_s=0.1, C_L=(1.6-2.0) d_Pω/|W^^→| and μ_d=0.12-0.20 were obtained for the Reynolds number R_e.p =2000-6000.