Fluid-elastic instability of rotated triangular array tube bundle in two-phase cross-flow

U-bend regions of nuclear steam generator tube bundle have been experienced fretting wear damage due to two-phase cross-flow fluid-elastic instability. Among many existing experiments, Pettigrew et al.'s works are worthy of attention. They found that above a certain void fraction critical flow velocities for the fluid-elastic instability were much lower than expected by the typical Connors' correlation. They explained that the above phenomenon is probably due to the flow regime transition from continuous to intermittent flow. However, such a fluid-elastic instability behavior with much lower critical flow velocities at intermittent flow conditions has not been clearly observed through other's experiments yet. Thus, it is the field that needs a further investigation. The main objectives of the present experiments are to investigate the flow regimes and the resultant fluid-elastic instability behaviors in a wide range of void fraction and to cross-check the effect of the intermittent flow