Effect of rolling on the flowing and heat transfer characteristic of turbulent flow in sub-channels

The flowing and heat transfer of turbulent flow in typical 4 rod bundles in rolling motion is investigated with LES and URANS. As the rolling period decreases, the average wall shear stress increases, and the frictional resistance increases. The wall shear stress solved by LES is not good enough, while that of URANS is consistent with experiments. The variation of frictional resistance coefficient, Nusselt number and Reynolds stress with rolling amplitude is very weak. In rolling motion, the biggest frictional resistance coefficient is not located in a constant time.