Studies on flow induced vibration of reactivity devices of 700MWe Indian PHWR

Operational modal analysis of flow-induced vibration of nuclear fuel rods in a turbulent axial flow

“…However direct integration does not provide information about the individual vibration modes or about the response between the measurement points. Furthermore and whilst traditional direct or FFT based techniques for nuclear fuel pins (and assemblies thereof) (IAEA- TWGFPT, 2005;Prabhakaran et al, 2012) -such as a peak detection method combined with modal bandwidth or modal magnification factor method -can be used to estimate modal parameters (Akishita et al, 2005), the accuracy of such techniques remains debatable. To cope with these shortcomings we used an adapted operational modal analysis technique (see also Fu and He, 2001;Guillaume et al, 2003;Ewins, 2000) in order to identify the system with high accuracy and precision under real operational conditions.…”

CFD analysis of moderator flow and temperature fields inside a vertical calandria vessel of nuclear reactor

“…Authors gives a plot between Archimedes number and Reynolds number which shows buoyancy dominated flow for Ar >0.40 and inlet jet momentum dominated for Ar <0.06. Prabhakaran et al (2012) carried out CFD analysis of moderator flow and temperature distribution in calandria of 700 MWe PHWR for flow-induced vibration. PHWR calandria has 12 moderator inlets near the horizontal center line of the calandria and four moderator outlets at the bottom of the calandria vessel.…”