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 the certain value. This abnormal vibration is defined to be self-excited vibration caused by leakage flow induced vibration here. In this study, as the first step, the theoretical model of non tapered clearance flow passage is assumed and the natural frequency is obtained. On that basis, experiments are performed and the validity of the theory is examined. As the second step, in case of tapered clearance flow passage, the concentrated load is added to the belt, and the effects of the belt deformation, the flow rate and the added loads on the clearance flow are examined. the generation mechanism of the abnormal vibration is considered. As a result, it was clarified that the presented theory was useful in case of non tapered clearance and the generation mechanism of the self-excited vibration was the phase shift due to the change of the parameters.
