Anti-Vibration Bar Model for the THIRST Computer Code''

Abstract

This paper presents the preliminary results of the numerical analysis done to investigate the effects of anti-vibration bars (AVBs) on the U-bend flow distribution in prototypical nuclear plant steam generator. A three-dimensional model shows that a single set of AVBs has little effect on the global thermalhydraulic results. However,there is a significant local effect on the velocity in control volumes which contain significant amounts of AVBs. Accurate estimates of local velocity are important for the vibrational analysis of the tubes. Modelling of a single set of AVBs at three different angles of inclination showed that the local effects were affected significantly by the AVB angle.