Improving Heat Flux Predictions for Directional Flame Thermometers by Incorporating Convective Effects
Improving Heat Flux Predictions for Directional Flame Thermometers by Incorporating Convective Effects
复制标题
通过结合对流效应改进定向火焰温度计的热通量预测
DOI：
10.1007/s10694-022-01263-w
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发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Ezekoye, Ofodike A.
中科院分区：
文献类型：
--
作者：
Franqueville, Juliette I.;Cabrera, Jan-Michael;Ezekoye, Ofodike A.
定向火焰温度计（DFT）是一种用于测量火灾场景中辐射热通量的装置。在许多DFT应用中，辐射是热传递的主要模式，对流对辐射热通量的预测没有显著影响。然而，在较高的空气速度，忽略对流导致热通量预测的错误。本研究探讨了忽略强制对流在热通量预测中所造成的误差，并提出了一种方法来减少它。为了实现这一点，前向传热模型被用来生成DFT给定的辐射和对流条件下的合成温度数据。使用的正演模型和现有的逆模型，这项研究表明，假设自然对流是唯一的对流传热模式导致预测的辐射热通量显着的误差。为了减少这个误差，这项工作提出了一个框架，恢复传热系数和辐射热通量在强制对流条件。该框架在DFT板上方使用额外的热电偶。该框架在空气流温度和热电偶温度低于15 ℃的模拟中表现不佳。平均而言，省略该条件成立的模拟，在恒定热通量和恒定特征空气速度条件下使用框架，与假设自然对流是唯一的对流模式预测热通量时相比，将预测热通量的误差降低了12倍。一个简单的实验测试进行验证的计算框架。
The directional flame thermometer (DFT) is a device used to measure radiative heat flux in fire scenarios. In many DFT applications, radiation is the dominant mode of heat transfer and convection does not significantly affect radiative heat flux predictions. However, at higher air velocities, neglecting convection causes error in heat flux predictions. This study explores the error caused by ignoring forced convection in heat flux predictions and proposes a method to reduce it. To accomplish this, a forward heat transfer model is used to generate synthetic temperature data for the DFT given radiative and convective conditions. Using the forward model and an existing inverse model, this study shows that assuming natural convection is the only mode of convective heat transfer leads to significant error in the predicted radiative heat flux. To reduce this error, this work proposes a framework for recovering the heat transfer coefficient and radiative heat flux in forced convection conditions. The framework utilizes an additional thermocouple above the plate of the DFT. The framework performed poorly for simulations in which the temperature of the air stream and that of the thermocouple was lower than 15C. Omitting simulations where this condition holds, on average, using the framework under constant heat flux and constant characteristic air velocity conditions reduces the error in the predicted heat flux by a factor of 12 compared to when the heat flux is predicted assuming that natural convection is the only mode of convection. A simple experimental test was conducted to validate the computational framework.
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DOI：
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发表时间：
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期刊：
影响因子：
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作者：
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DOI：
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发表时间：
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期刊：
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DOI：
10.1115/1.4046657
发表时间：
2020
期刊：
Validation and Uncertainty Quantification
影响因子：
--
作者：
Cabrera, J. M.;Moser, R. D.;Ezekoye, O. A.
通讯作者：
Ezekoye, O. A.