A modeling approach to account for unstable stratification, flow acceleration, and variable thermophysical properties for supercritical carbon dioxide
A modeling approach to account for unstable stratification, flow acceleration, and variable thermophysical properties for supercritical carbon dioxide
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DOI：
10.1016/j.ijheatmasstransfer.2022.122537
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发表时间：
2022
影响因子：
5.2
通讯作者：
S. A. Jajja;Lindsey V. Randle;B. Fronk
中科院分区：
文献类型：
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作者：
S. A. Jajja;Lindsey V. Randle;B. Fronk
第一个其类型的降阶预测传热模型被开发，以解释不稳定的分层，流动加速，以及超临界二氧化碳的可变热物理性质的影响。当施加的加热仅限于流道底壁时，这些现象控制了伪临界点附近的热输运。降阶模型假设二维热输运，并涉及湍流普朗特数的迭代解。该模型的预测结果与实验数据进行了比较。在总共16个测试数据集中，每个数据集包含超过200个单独的数据点，该模型能够预测14个数据集的平均平均百分比误差（MAPE）小于20%。在此基础上，提出了一种能在小于22%的误差下预测实验数据的传热设计关联。本研究概述的建模方法提供了一种替代方法，可以使用CFD来模拟控制非对称底部加热管道中超临界流体热传输的耦合和抵消现象。
A first of its kind reduced-order predictive heat transfer model is developed to account for the effects of unstable stratification, flow acceleration, and variable thermophysical properties for supercritical carbon dioxide. These phenomena govern thermal transport in the proximity of the pseudo-critical point when the applied heating is limited to the bottom wall of the flow channel. The reduced order model assumes two-dimensional thermal transport and involves the iterative solution of the turbulent Prandtl number. The predictions of this model were compared against experimental data. Out of a total of 16 test data sets, each comprising over 200 individual data points, the model was able to predict 14 data sets with a mean average percent error (MAPE) of less than 20%. Additionally, a heat transfer design correlation is proposed which can predict the experimental data with aMAPEof less than 22%. The modeling approaches outlined in this work provide an alternative to using CFD to model coupled and counteracting phenomena that governs thermal transport for supercritical fluids in asymmetrically bottom heated ducts.