An experimental investigation of effects of angular misalignment on flow-induced vibration of simulated CANDU fuel bundles

This paper presents an experimental investigation of effects of angular misalignment on flow-induced vibration of two simulated 43-element CANDU fuel bundles in an out-reactor fresh water loop. A total of 11 different alignment configurations are examined for a range of mass flow rates from 8.56 kg/s to 27.36 kg/s. The dynamic response of the simulated bundles is acquired using the MEMS-based accelerometers, non-contact type displacement sensor and a data acquisition system. The experimental data show that the bundle lateral vibration is sensitive to the bundle angular misalignment; there exist few misalignment configurations which exhibit significantly large bundle lateral vibration. This is an indication that the flow in the bundle-to-bundle interface region plays an important role in flow-induced vibration of CANDU fuel bundles.

► Conducted experiments on flow-induced vibration of simulated 43-element CANDU bundles with angular misalignment. ► Found that complex flows through interface regions between neighboring bundles is the main source of excitation. ► Found that dynamic responses of fuel bundles are sensitive to bundle misalignment angles.