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Combined modeling and experimental validation of boiling curve and critical heat flux.

机译：沸腾曲线和临界热通量的组合建模和实验验证。

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A model is developed to give combined predictions of the subcooled nucleate boiling heat transfer curve and the critical heat flux. Each component of the heat flux due to various heat transfer mechanisms, including forced convection, transient conduction, and microlayer evaporation, is identified and quantified. The key effects of bubble coalescence are modeled from a statistical approach by deriving the probability density function of bubble interaction to develop the distribution of the bubble lift-off radius. It is found from this mechanistic approach that the critical heat flux reflects a limit of heat transfer capacity imposed by the interaction of bubbles.; To verify this model, experiments are conducted for a range of conditions. A highspeed, high-fidelity imaging system is employed to quantitatively investigate the bubble motion. Predictions are compared with experimental measurements in this study as well as data available in the literature, with an overall good agreement achieved. An average error of +/-25% is observed for the boiling curve prediction, while for the critical heat flux the prediction error is limited within +/-20%, which equals or supersedes most available semi-empirical models or correlations. This model captures and correctly describes the stochastic nature of the flow and thermal variations, as well as the tightly coupled bubble motion in the flow and thermal fields. This suggests that to extend the modeling of subcooled nucleate boiling to predict critical heat flux, both probabilistic formulation and stochastic analysis need to be utilized.

机译：开发了一个模型，以给出过冷核沸腾传热曲线和临界热通量的组合预测。由于各种传热机制（包括强制对流，瞬态传导和微层蒸发）而产生的热通量的每个成分都得到了识别和量化。通过推导气泡相互作用的概率密度函数来发展气泡提离半径的分布，从统计方法中模拟了气泡合并的关键效果。从这种机械方法中发现，临界热通量反映了气泡相互作用引起的传热能力的极限。为了验证该模型，在一定条件下进行了实验。高速，高保真成像系统用于定量研究气泡运动。在本研究中，将预测结果与实验测量结果以及文献中的数据进行了比较，总体上取得了良好的一致性。对于沸腾曲线预测，观察到平均误差为+/- 25％，而对于临界热通量，预测误差被限制在+/- 20％之内，该误差等于或取代大多数可用的半经验模型或相关性。该模型捕获并正确描述了流量和热变化的随机性质，以及在流量和热场中紧密耦合的气泡运动。这表明，为了扩展过冷核沸腾的模型以预测临界热通量，既需要利用概率公式，也需要进行随机分析。

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作者
Wu, Wen.;
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作者单位

University of Illinois at Urbana-Champaign.;

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授予单位 University of Illinois at Urbana-Champaign.;
学科 Engineering Mechanical.; Engineering Nuclear.
学位 Ph.D.
年度 2007
页码 145 p.
总页数 145
原文格式 PDF
正文语种 eng
中图分类机械、仪表工业;原子能技术;
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机译：沸腾危机和临界热通量。

Combined modeling and experimental validation of boiling curve and critical heat flux.

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