Study of a lead-bismuth eutectic jet issued into a heated cavity using large eddy simulation
Study of a lead-bismuth eutectic jet issued into a heated cavity using large eddy simulation
复制标题
使用大涡模拟研究进入加热腔的铅铋共晶射流
DOI：
10.1016/j.ijheatmasstransfer.2022.123407
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发表时间：
2022
影响因子：
5.2
通讯作者：
Huang X
中科院分区：
文献类型：
--
作者：
Huang X
采用大涡模拟方法研究了铅铋共晶（LBE）轴对称湍流射流进入加热受限几何体后的低普朗特数对流。基于射流中心线速度和射流直径的雷诺数为Re = 44，706。结果表明，液态金属的一些特点，偏离那些普通的流体。例子包括温度和速度的波动之间的差异，湍流粘度和湍流热扩散率的分布，以及湍流热通量矢量和平均温度梯度之间的不对准，所有这些都意味着标准湍流模型可能不适合于模拟这种流动。在相同的Re和Fr条件下，对Pr = 0.03的LBE射流和Pr = 0.8的高压水射流进行了比较。LBE的平均速度的中心线衰减表现出与水的相同的行为，这是由在1.5D和8.5D之间的自我保存区域的线性变化，其中D是喷射孔的直径。与此相反，LBE的中心线平均温度的下降速度慢于水。温度的差异是由于在LBE中热传输中分子扩散的高强度，而在两种流动中动量传输主要是通过湍流扩散。观察到温度均方根值（Trms）的自保持特性。Trms的径向轮廓由轴对称曲线表示，最大值在0.7b附近，其中b是Trms的半值半径。计算结果与实验结果吻合较好。
Low Prandtl number convection of an axisymmetric turbulent lead-bismuth eutectic (LBE) jet discharged into a heated confined geometry using large eddy simulation is investigated. The Reynolds number based on jet centerline velocity and jet diameter isRe= 44,706. The results demonstrate some features of liquid metal that deviate from those of ordinary fluids. Examples include the differences between fluctuations of temperature and velocity, the distributions of turbulent viscosity and turbulent diffusivity of heat, and the misalignment between the turbulent heat flux vector and the gradient of mean temperature, all of which imply that standard turbulence models may not be suitable for the simulation of such flows. The LBE jet atPr= 0.03 is compared with a high-pressure water jet atPr= 0.8 under the sameReandFr. The centerline decay of the mean velocity for LBE demonstrates the same behavior as that of water, which is governed by a linear variation for the self-preservation region between 1.5Dand 8.5D, whereDis the diameter of the jet orifice. In contrast, the centerline mean temperature for LBE decreases slower compared with that of water. The difference in temperature results from the high intensity of molecular diffusion in heat transport in LBE, while the momentum transport is mainly by turbulent diffusion in both flows. Self-preserving characteristic of temperature r.m.s (Trms) is observed. The radial profiles ofTrmsare presented by an axisymmetric curve with a maximum at around 0.7b, wherebis the half-value radius ofTrms. Good agreement of mean temperature distribution between the simulation results and the experiments are obtained.