In this work, an in-house developed multiphysics unsteady approach (U-THERM3D) is employed to compute wall temperatures in a loosely coupled manner for a model aero-engine combustor, fueled with a non-premixed ethylene/air mixture and representative of the RQL technology. Large-Eddy Simulation (LES) is carried out to prove that scale-resolving approaches are required for a reliable prediction of turbulent mixing with respect to steady-state methods. A Flamelet Generated Manifold approach is adopted to describe the reactive flow, whereas two additional transport equations are included to predict the soot concentration. For a thorough investigation of the considered aero-engine combustor, cold flow results are firstly presented, highlighting the importance of an accurate predictions of general flow features. Then, the aerothermal fields are analysed to show the overall accuracy of the developed approach and so the impact of heat losses, comparing the results of an adiabatic simulation with respect to the loosely coupled conjugate heat transfer calculation. Finally, the investigation is focused on the prediction of the wall temperature distribution to prove the advantages of the U-THERM3D procedure with respect to steady-state approach.

中文翻译：

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使用多物理场方法对模型航空发动机烟灰火焰进行大涡模拟

在这项工作中，采用内部开发的多物理场非定常方法 (U-THERM3D) 以松散耦合的方式计算模型航空发动机燃烧室的壁温，该燃烧室以非预混乙烯/空气混合物为燃料，并代表RQL 技术。进行大涡模拟 (LES) 以证明需要尺度解析方法来可靠地预测相对于稳态方法的湍流混合。采用 Flamelet Generated Manifold 方法来描述反应流，同时包含两个额外的传输方程来预测烟尘浓度。为了对所考虑的航空发动机燃烧室进行彻底调查，首先提出冷流结果，突出了准确预测一般流动特征的重要性。然后，对空气热场进行了分析，以显示所开发方法的整体准确性以及热损失的影响，并将绝热模拟的结果与松散耦合共轭传热计算的结果进行比较。最后，调查的重点是壁温分布的预测，以证明 U-THERM3D 程序相对于稳态方法的优势。