2007 年 7 巻 4 号 p. 393-397
The stress in granular media flowing from the 2D hopper with an orifice is visualized by experimental method using photoelasticity. Firstly, the characteristics of the granular flow are examined. The results show that critical outlet diameter of the granular flow is about five times larger than the diameter of the particle used in this study. Moreover, the characteristic of the mass flow rate nearly corresponds with that in general granular flow systems. Then, the stress in the granular flow is examined through the photoelastic experiment. The results show that dynamic arches are frequently observed near the orifice even if the granular flows out from the orifice continuously. The rate of arching during granular flowing and the frequency of clogging increase with decreasing the orifice bore. These results say that the static arching and clogging are caused by increasing of the rate of dynamic arching.