摇摆条件下子通道内湍流流体的数值分析

利用FLUENT软件分析了摇摆条件对典型四棒束间的湍流流体流动和传热特性的影响机理。摇摆运动会对棒束间流体的流动传热特性产生一定影响。RSM模型可以很好地描述摇摆条件下子通道内的参数分布。摇摆周期变化带来的径向附加力的变化不会对摩擦阻力系数、传热系数和Reynolds应力产生影响。在摇摆条件下，摩擦阻力系数、传热系数和Reynolds应力呈周期性变化，但最大摩擦阻力系数所在时刻并不固定，而最大传热系数却始终是在流速最大的时刻。

Numerical Analysis of Turbulent Flow in Subchannels Under Rolling Motion Condition

The influence mechanism of rolling motion on the flowing and heat transfer characteristics of turbulent flow in typical four rod bundles was investigated with FLUENT code. The flowing and heat transfer characteristics of turbulent flow in rod bundles can be affected by rolling motion. The parameters in subchannels under rolling motion condition can be described very well with RSM model. The variation of radial additional force due to the variation of rolling period does not affect on the frictional resistance coefficient, heat transfer coefficient and Reynolds stress. Under rolling motion condition, the frictional resistance coefficient, heat transfer coefficient and Reynolds stress oscillate periodically. However, the occurring time of maximum frictional resistance is not constant, while the maximum heat transfer coefficient occurs when the flow velocity is the maximum.