稠密栅元内湍流流体的数值模拟

Numerical Simulation of Turbulent Flow in Tight Lattice

1.
Department of Nuclear Energy Science and Engineering, Naval University of Engineering, Wuhan 430033, China
2.
School of Nuclear Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

摘要: 采用CFD软件Fluent对37棒束内的湍流流体进行了分析。利用实验数据对计算结果进行了验证，分析了棒棒间隙的减小对稠密栅元内局部流动、传热和相干结构的影响。稠密栅元的临界P/D（棒间距/棒直径）约为1.03。随着P/D减小，相干结构和流体交混先增加然后迅速衰减。当通道间隙非常小时，相干结构运动非常弱以至于可将其忽略。其流速、壁面剪应力和壁面温度的波动也非常小，但其参数的空间分布的差异非常明显。
- 湍流 ,
- 稠密栅元 ,
- 相干结构
Abstract: The turbulent flow in 37 rod bundles was investigated with CFD code Fluent. The calculation results were validated with experimental data. The effects of diminishing rod-rod gap size on local flow, heat transfer and coherent structure in tight lattice were analyzed. The critical pitch to diameter ratio is next to 1.03. As the decreasing of pitch to diameter ratio, the coherent structure and flow mixing increase first and then decay sharply. In the very narrow gap, the coherent structure is so weak that it can be omitted. The oscillations of velocity, wall shear stress and wall temperature are also very weak. But the spatial difference of the parameters in this gap is very significant.
- turbulent flow ,
- tight lattice ,
- coherent structure

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