CFD analysis of turbulent heat transfer in a heated rod bundle

A CFD analysis has been performed to investigate turbulent heat transfer in a triangular rod bundle with a Pitch-to-Diameter ratio(P/D) of 1.06. Anisotropic turbulence models predicted the turbulence-driven secondary flow in the triangular subchannel and the distributions of time mean velocity and temperature showing significantly improved agreement with the measurements over the linear standard κ-ε model. The anisotropic turbulence models predicted turbulence structure in large flow region fairly well but could not predict the very high turbulent intensity of azimuthal velocity observed in narrow flow region(gap)