Abstract
This paper focuses on the numerical simulation of turbulence mixing phenomena in tight lattice geometries. Transient calculation with the explicit algebraic Reynolds stress model for turbulent mixing has been carried out. The main features of the turbulence structures and the turbulent mixing rate between the channels are successfully reproduced. The mixing rate is strongly enhanced by the periodic flow pulsation. The calculation results of mixing rate shows good agreement with the experiment. The characteristics of the flow pulsation as well as the turbulent mixing coefficient under various types of subchannels with different P/D and Reynolds number were investigated. Finally a new correlation was obtained for turbulent mixing in subchannels based on the numerical simulation results.
