T型三通管冷热流体掺混数值模拟

摘要

针对T型三通管冷热流体掺混现象经常引发管道热疲劳甚至部件失效的问题, 基于FLUENT混合雷诺平均N-S方程 (Reynolds averaged N-S equations, RANS) 和大涡模拟 (large eddysimulation, LES) 方法, 对其管内冷热流体掺混问题进行仿真模拟.对划分的LES和RANS计算域分别采用壁面模拟LES (wall-modeled LES, WMLES) 和k-ωSST模型进行计算, 并将数值模拟结果与实验数据进行对比.分析功率谱密度 (power spectral density, PSD), 预测管内冷热流体掺混过程的热疲劳敏感位置, 结果表明:数值模拟预测结果与实验数据吻合度较高, 热疲劳敏感位置也与实际情况相符合.混合RANS-LES方法适用于T型三通管冷热流体掺混问题研究.%As to the issue that the cold-hot fluid mixing in T-junction is easy to lead to thermal fatigue and component failure, the cold-hot fluid mixing in T-junction is simulated combining Reynolds averaged N-S equations (RANS) and large eddy simulation LES method based on FLUENT. The LES and RANS calculation domains are calculated by wall-modeled LES (WMLES) model and k-ω SST model respectively, and the numerical simulation results are compared with the experimental data. The power spectral density (PSD) is analyzed, and the thermal fatigue sensitive location of cold-hot fluid mixing process in T-junction is predicted. The results show that, the predicted results of numerical simulation agree well with the experimental data, and the location of thermal fatigue sensitivity is also consistent with the actual situation. The hybrid RANS-LES method is suitable for the study of cold-hot fluid mixing of T-junction.