International Journal of Heat and Fluid Flow ( IF 2.6 ) Pub Date : 2021-04-21 , DOI: 10.1016/j.ijheatfluidflow.2020.108728 S. Silvestri , D.J.E.M. Roekaerts , R. Pecnik
The present work investigates the modeling of turbulent heat transfer in flows where radiative and convective heat transfer are coupled. In high temperature radiatively participating flows, radiation is the most relevant heat transfer mechanism and, due to its non-locality, it causes counter intuitive interactions with the turbulent temperature field. These so-called Turbulence-Radiation Interactions (TRI) largely affect the temperature field, modifying substantially the turbulent heat transfer. Therefore, in the context of modeling (RANS/LES), these interactions require a closure model. This work provides the inclusion of TRI in the modeling of the turbulent heat transfer by adopting a unique approach which consists in approximating the fluctuations of the radiative field with temperature fluctuations only. Based on this approximation, coefficients of proportionality are employed in order to close the unknown terms in the relevant model equations. A closed form of all radiation-temperature-velocity correlation is explicitly derived depending on the chosen turbulent heat transfer model. This model is applied to a standard two-equation turbulent heat transfer closure and used to reproduce results obtained with high-fidelity DNS simulations. While a standard approach (i.e., neglecting TRI) is not able to correctly predict the DNS data, the new model’s results shows exceptional agreement with the high-fidelity data. This clearly proves the validity (and the necessity) of the proposed model in non-reactive, radiative turbulent flows.
中文翻译:
湍流与辐射相互作用的湍流通量建模
本工作研究了耦合辐射和对流传热的湍流传热模型。在高温辐射参与流中,辐射是最相关的传热机制,并且由于其非局部性,它导致与湍流温度场产生反直观的相互作用。这些所谓的湍流-辐射相互作用(TRI)在很大程度上影响温度场,从而大大改变了湍流的热传递。因此,在建模(RANS / LES)的上下文中,这些交互需要封闭模型。这项工作通过采用独特的方法将TRI包括在湍流传热的建模中,该方法仅用温度波动来近似辐射场的波动。根据这个近似值,为了封闭相关模型方程中的未知项,采用了比例系数。根据所选的湍流传热模型,可以明确得出所有辐射-温度-速度相关性的闭合形式。该模型应用于标准的两方程式湍流热传递闭合,并用于重现通过高保真DNS模拟获得的结果。尽管标准方法(即忽略TRI)无法正确预测DNS数据,但新模型的结果显示出与高保真数据的出色一致性。这清楚地证明了所提出的模型在非反应性辐射湍流中的有效性(和必要性)。根据所选的湍流传热模型,可以明确得出所有辐射-温度-速度相关性的闭合形式。该模型应用于标准的两方程式湍流热传递闭合,并用于重现通过高保真DNS模拟获得的结果。尽管标准方法(即忽略TRI)无法正确预测DNS数据,但新模型的结果显示出与高保真数据的出色一致性。这清楚地证明了所提出的模型在非反应性辐射湍流中的有效性(和必要性)。根据所选的湍流传热模型,可以明确得出所有辐射-温度-速度相关性的封闭形式。该模型应用于标准的两方程式湍流热传递闭合,并用于重现通过高保真DNS模拟获得的结果。尽管标准方法(即忽略TRI)无法正确预测DNS数据,但新模型的结果显示出与高保真数据的出色一致性。这清楚地证明了所提出的模型在非反应性辐射湍流中的有效性(和必要性)。尽管标准方法(即忽略TRI)无法正确预测DNS数据,但新模型的结果显示出与高保真数据的出色一致性。这清楚地证明了所提出的模型在非反应性辐射湍流中的有效性(和必要性)。尽管标准方法(即忽略TRI)无法正确预测DNS数据,但新模型的结果显示出与高保真数据的出色一致性。这清楚地证明了所提出的模型在非反应性辐射湍流中的有效性(和必要性)。