流量波动条件下圆管内流动换热特性数值研究

对流量波动条件下核动力装置系统圆管内流体的流动换热特性进行了数值研究,重点研究了波动周期、波动振幅两个因素对流动换热特性的影响。结果表明:流量波动时,通道内的摩阻系数和壁面换热系数均随时间周期性波动,且波动周期与流量波动周期相同;波动周期增加,摩阻系数波动幅值减小,壁面换热系数波动振幅变化不明显;相对振幅增加,摩阻系数波动幅值增大,壁面换热系数波动振幅增大。

Numerical Simulation of Fluid Flow and Heat Transfer Characteristics under Flow Fluctuation Condition in Circular Tube

Flow and heat transfer characteristics in-a circular tube of nuclear power system under flow fluctuation condition are investigated numerically. The influences of the flow fluctuation period and relative amplitude on flow and heat transfer characteristics are mainly analyzed. The results show that the pressure drop, friction coefficient, wall heat transfer coefficient vary in sin law with time as flow fluctuates. What is more, their periods are the same with flow fluctuation period. In addition, the amplitude of friction coefficient decreases as flow fluctuation period becomes larger, while the amplitude of wall heat transfer coefficient increases. From a relative amplitude point of view, the parameters including friction coefficient, wall heat transfer coefficient increase when relative amplitude becomes larger.