载气入口速度与超细干粉灭火剂流动阻力关系的模拟实验研究

he motion characteristics of superfine BC powder extinguishing agent,which mean diameter is 18.7um, in the horizontal pipe with 5m/s beginning inlet velocity of carrier gas was studied based on Fluent and Eulerian two-phase flow model. The result shows that the resistance reduce with the decrease of the inlet velocity.According to the results of powder concentration and velocity distribution figures, it can be found that when the inlet velocity was low, the powder concentration at the top of the pipe is minimum and the bottom is maximum. The resistance is relatively weak, and it's mainly caused by shear stress and drag force. While,when the inlet velocity was fast, the powder concentration inside the pipe is like a ring, the velocity distribution is similar to single-phase flow. Under this conditin, drag force and shear force were enhanced, so as to cause the increase of the pressure drop. Also,the relationship between carrier gas velocity and per unit length pressure drop was studied, the results shows that each certain flow has a transition velocity, and the velocity increases with the increase of the powder flow rate.