Experimental investigation on fluid–structure interaction phenomenon caused by the flow through double-plate structure in a narrow channel

Highlights: ► Performing the flow induced vibration experiment of the double-plate structure. ► Solving the measure difficulty of actual structure of the fuel assembly. ► Measuring the amplitude and frequency of the two plates by optical measurement. ► Founding a new mechanism of flow induced vibration. ► The vibration mechanism of the double-plate is similar to the single-plate structure. In addition, we found the synclastic movement and the reverse movement of the double plates. - Abstract: An experiment was carried out to research fluid–structure interaction (FSI) phenomenon on the parallel-plate fuel assembly. The parallel-plate fuel assembly was simplified as a double-plate structure installed in a narrow rectangular channel. In the experiment, the narrow-frequency, large-amplitude and opposite-phase vibrations and same-phase bends of two plates were observed in the different flow rate ranges. Compared with the behaviors found in the single-plate structure, some different characteristics were discovered.