Scaled-up Test Research Articles

Experimental study on active suppression by gas bubble injection for earthquake induced sloshing in tanks.

This research aims to develop a technique to suppress liquid sloshing vibration in a tank by injecting air bubbles in a microcomputer-controlled manner. Using a rectangular tank 800 mm long, 1500 mm wide, and 500 mm high, installed on an oil-hydraulically controlled shaking table, sloshing was excited by a sinusoidal motion of the table and air was injected at each end of the test-tank bottom. The timing and duration of air injection were controlled by a microcomputer using the pressure signal caused by sloshing. Experiments showed that the most effective timing of air injection was the instant that the sloshing wave was ascending from the lowest position to the equilibrium one, and a small amount of air, equivalent to 1 to 3% of the water contained in the tank, was sufficient to suppress sloshing. A scaled-up test showed a similar effectiveness in reducing sloshing. An algorithm for controlling air-injection timing and duration was developed using knowledge obtained from the experiments.