抄録
The FDC (Flow Dynamics Conveyer) has been often used in power plants and iron works because of superiority in quiet compared with a roller type conveyer and it is excellent in a low noise and low power. The FDC consists of a trough and a belt, and the air is supplied from a lot of holes provided on the trough. However, large vibrations occur when the flow rate becomes a certain value. This abnormal vibration is defined to be self-excited vibration caused by leakage flow induced vibration here. It is well known that the abnormal vibration occurs when the tapered flow channel is formed. The purpose of this study is to clarify the generation mechanism of the abnormal vibration. The experiment was carried out to examine the effect of various parameters such as taper angle θ, floating amount H on the abnormal vibration. As a result, the damping ability becomes small with increase of the taper angle and decrease of the floating amount. Furthermore it was clarified that the abnormal vibration occurs in θ>0.11H.
