Abstract:
There are heat transfer correlations for heat transfer analysis in single tube geometries after several experimental
and theoretical heat transfer studies in these single tube geometries. This is not the case for heat transfer analysis
in rod bundle geometry with regard to proposed square fuel assembly of the Supercritical-Water-Cooled Reactor
(SCWR) European Atomic Energy (EURATOM) design. Thus limited heat transfer studies exist on rod bundle
geometry at supercritical pressures. Heat transfer correlations with accurate prediction capabilities of coolant and
wall temperatures will be helpful in carrying out heat transfer studies at supercritical pressures. This paper
presents the performance of twelve selected heat transfer correlations assessed on the 1/8th bare square fuel
assembly of the SCWR EURATOM design using Simulation of Turbulent flow in Arbitrary Regions Computational
Continuum Mechanics C þþ based code (STAR-CCM þ CFD code). The obtained numerical results were compared
with the results obtained by Waata numerical experimentation. Overall, the Cheng et al. correlation provided the
most satisfying prediction for the wall temperatures in all the sub-channels and captured closely Wataa's Numerical
data. The maximum wall temperature was obtained in sub-channel 9, the hottest sub-channel and
exceeded the design limit 620 C by 60 C for the Cheng correlation. The difference in temperature between the
hottest and coldest sub-channels 9 and 1 respectively was approximately 80 C. It was found that Cheng correlation
is best suited for heat transfer prediction in rod bundle geometry at supercritical pressures with regard to
the proposed square fuel assembly of the SCWR EURATOM design. It was also found that the different numerical
tools adopted for this study and Waata study were able to capture the trends of normal, enhanced and deteriorated
heat transfer regimes normally observed at supercritical pressures. Nevertheless, experimental investigations
involving rod bundles adopted in this study should be conducted to validate the results obtained numerically and
address the inconsistency of the conclusions drawn when compared with Waata data and other similar studies.
