Experimental Study on Self-Excited Vibration Characteristics of a Flexible Weir due to Fluid Discharge.

This paper deals with the characteristics of unstable self-excited vibrations of a rectangular, flexible weir installed in a tank, over which water in the upstream tank discharges into the down-stream one. Experiments were carried out for measuring the vibrational strains of the weir, and the oscillation of the water surface in the up-stream tank with changing inlet velocity of water and discharge height. We examined the vibration characteristics of the weir with changing tank ratio (defined as the down stream tank length/the upstream tank length), and found that the occurrence of unstable vibration depends strongly on the tank ratio. The phase relations of the weir vibration to the upstream tank water oscillation were experimentally investigated.