基于图神经网络的非均匀壁温气动热预测方法
A GRAPH NEURAL NETWORK-BASED METHOD FOR AEROHEATING PREDICTION UNDER NON-UNIFORM WALL TEMPERATURE CONDITIONS
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摘要: 数据驱动的热流预测模型可以实现对气动热的快速及准确预测, 具有很大的发展潜力. 现有数据驱动的热流预测方法大多基于等温壁发展, 而实际飞行器由于流固耦合传热等效应其壁面温度分布并不均匀, 因此文章的研究目标是发展一种适用于非均匀壁温条件下的气动热预测方法. 首先利用CFD开展数值实验, 证明上游壁面的温度分布会对下游壁面的热流产生明显影响; 之后, 基于图神经网络方法引入上游壁温分布的影响, 并通过带有注意力机制的信息聚合方式计算上游不同点的影响权重, 进而发展了一种非均匀壁温的气动热预测方法. 在此基础上, 针对典型算例设计了非均匀壁温的气动热数据集并进行神经网络的训练, 在测试集上的预测结果表明, 该方法的热流预测相对误差均低于6%, 而传统只考虑当地壁温的热流预测模型最大预测误差超过15%. 最后, 将所发展的气动热预测模型与固体导热求解相结合, 实现了基于代理模型的流固耦合传热模拟, 计算结果表明不同时刻流固交界面温度分布相对基于CFD的结果误差均小于5%.Abstract: Data-driven heat flux prediction models enable fast and accurate predictions of aerodynamic heat, demonstrating significant potential for further development. Most existing data-driven heat flux prediction methods are developed under the assumption of isothermal walls. However, in real aircraft, the wall temperature distribution is far from uniform due to the coupling of fluid-solid heat transfer. As such, the primary objective of this research is to develop an aerodynamic heat prediction method that is capable of addressing non-uniform wall temperature conditions. To address this issue, the study employs CFD-based numerical experiments to demonstrate that the temperature distribution on the upstream wall significantly affects the heat flux on the downstream wall. This finding highlights the necessity of incorporating upstream temperature information when predicting heat flux on downstream surfaces. To further address this, based on graph neural network (GNN), the influence of the upstream wall temperature distribution is incorporated. By employing an attention mechanism for information aggregation, the impact weights of different upstream points are computed, resulting in the development of a heat flux prediction method for non-uniform wall temperatures. Based on this, a dataset for aerodynamic heat flux under varying wall temperature conditions is constructed, and the GNN-based model is trained on this data. The model’s performance is evaluated on the test set, and the results indicate that the relative error in heat flux predictions consistently remains below 6%. In contrast, traditional models that consider only the local wall temperature exhibit maximum prediction errors exceeding 15%. Finally, the developed aerodynamic heat prediction model is integrated with a solid conduction solver to conduct surrogate model-based fluid-solid coupled heat transfer simulations. The results demonstrate that the relative error in the temperature distribution at the fluid-solid interface at different times is less than 5% compared to CFD-based results.