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基于常压下竖直窄缝通道的过冷沸腾实验结果,提出了2 mm窄缝通道的壁面核化数值新模型,模型包括:汽化核心密度、气泡脱离直径、气泡脱离频率和核化起始点(ONB)关联式。分别采用新模型和CFX模型对典型实验工况进行数值模拟分析,模拟结果与实验的壁面温度和平均壁面温度结果吻合较好。详细讨论了2个模型中的3个主要关联式的差异,最后讨论了ONB模型对过冷沸腾数值模拟结果的影响。结果表明,考虑ONB模型的新核化模型能更准确地预测窄缝通道过冷流动沸腾传热特性。
Based on the experimental results of subcooling boiling at vertical narrow channel at atmospheric pressure, a new numerical model of wall nucleation of 2 mm narrow channel was proposed. The model includes the core density of vaporization, the diameter of bubble separation, the frequency of bubble detachment and the initiation of nucleation (ONB) correlation. The new model and CFX model are respectively used to analyze the typical experimental conditions. The simulation results are in good agreement with the experimental wall temperature and average wall temperature. The differences of the three main correlations in the two models are discussed in detail. Finally, the effects of the ONB model on the numerical simulation of subcooled boiling are discussed. The results show that the new nucleation model considering the ONB model can predict the heat transfer characteristics of the supercooling flow in a narrowed channel more accurately.