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以90°弯头在高温气冷堆内的特殊应用为背景,运用大涡模拟方法对90°弯头内的复杂流场进行了数值模拟,并将时均化处理后的结果与实验结果以及RANS稳态模拟结果进行了综合对比。通过对内、外弧面特定监测点的压力脉动信号进行功率谱密度分析,研究了在流动分离和二次流共同作用下弯头内压力脉动的特点。研究结果表明,压力脉动在内、外弧面上的成因不同。内弧面上最大压力脉动功率出现在弯曲角度50°附近区域,主要由流动分离和涡脱落引起;外弧面上最大压力脉动功率出现在弯曲角度12°附近区域,由流体与外弧面的冲击作用引起。
Based on the special application of 90 ° elbow in HTGR, a large eddy simulation method was used to simulate the complex flow field in a 90 ° elbow. The results of time-averaged treatment and experimental results, as well as RANS steady-state simulation results for a comprehensive comparison. By analyzing the power spectral density of the pressure pulsation signals at the specific monitoring points inside and outside the arc surface, the characteristics of the pressure pulsation in the elbow under the combined action of flow separation and secondary flow were studied. The research results show that the causes of pressure fluctuation are different on the outer arc surface. The maximum pressure pulsating power on the inner arc appears in the region of 50 ° bending angle and is mainly caused by the flow separation and vortex shedding. The maximum pressure pulsation power on the outer arc appears in the region of 12 ° bending angle, Impact caused by.