基于深度算子网络的升力体气动力预测方法
DEEPONET FOR AERODYNAMIC FORCE PREDICTION OF LIFTING BODY
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摘要: 在升力体飞行器的外形设计过程中, 引入气动性能计算环节对外形进行基于气动性能结果的实时精细修形可实现升力体飞行器外形的高效迭代优化. 但如果此过程中气动计算环节耗时较长, 依旧会导致后续外形迭代更新的效率问题, 解决这一问题的关键是采用一种兼具精度与计算速率的气动预测代理模型, 实现以往CFD方法在气动计算环节中的功能. 本文采用深度算子网络(DeepONet)结构构建并训练一类气动力预测代理模型, 实现对使用特征外形参数表征的升力体外形在不同工况下的气动力预测. 升力体气动力预测模型的核心是设置外形参数编码层对特征外形参数进行预处理, 使其在潜在空间与工况参数实现维度对齐, 以兼顾外形和工况对气动结果的共同影响, 以及使用深度算子网络中的分支子网络引入全局数据空间信息, 指导各个数据子空间训练. 结果显示, 基于深度算子网络的升力体气动力预测模型对主要气动力的平均预测误差均小于3%, 取得良好气动力预测精度的同时, 对比非神经网络架构的Kriging和径向基函数(RBF)具有显著精度优势; 对比一般深度神经网络结构, 基于深度神经算子网络的升力体气动力预测模型的总体平均预测误差减小16.4%.Abstract: In the aerodynamic shape design of lifting-body vehicles, integrating aerodynamic performance evaluation into the design loop enables real-time, performance-driven fine-tuning of the vehicle geometry, thereby facilitating efficient iterative optimization. However, if the aerodynamic analysis step remains computationally expensive, it can still hinder the overall efficiency of subsequent shape updates. Addressing this challenge requires a surrogate model that balances high predictive accuracy with computational speed, effectively replacing conventional computational fluid dynamics (CFD) methods in the aerodynamic evaluation stage. This paper presents a surrogate model for aerodynamic force prediction based on the DeepONet architecture. The model is trained to predict aerodynamic forces acting on lifting-body configurations parameterized by a set of geometric descriptors. A key innovation of the proposed approach lies in the incorporation of a geometry-parameter encoding layer, which preprocesses the geometric descriptors to align their latent representation with the dimensionality of the operating-condition parameters. This alignment ensures that both geometric and operational factors are jointly accounted for in the prediction. Furthermore, the branch network of DeepONet is leveraged to inject global information from the entire data space into the training of individual data subspaces, enhancing model generalization. Numerical results demonstrate that the DeepONet-based surrogate model achieves mean prediction errors of less than 3% for primary aerodynamic forces, indicating high predictive fidelity and significant improvement in accuracy compared to non-neural-network approaches such as Kriging and Radial Basis Function (RBF) interpolation. Compared to general deep neural network architectures, the proposed DeepONet-based model reduces the overall average prediction error by 16.4%, underscoring its superior performance in aerodynamic force estimation for lifting-body vehicles.
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