Simulation of Thermal-Hydraulic Behavior in Tight Lattice Rod Bundle

The turbulence air thermal-hydraulic behavior inside the center and wall channel in tight lattice bundles is investigated.The wall temperature,wall shear stress,bulk temperature,bulk velocity,turbulent kinetic energy and turbulent mixing rate are analyzed by comparing the computational results with experimental data.The results show the increase of the non-uniformity of the parameters in tight lattice and the discrepancy between the calculation and the experiment with the decrease of P/D,and a temperature maximum appears in the gap region.This should be taken into account in the design of the fuel assembly with tight lattices.It is necessary to take the circumferential heat conduction of the channel wall into consideration in the simulation.