Fusion of Simulation and Experiment Data for Hypersonic Flow Field Prediction via Pre-Training and Fine-Tuning

TL;DR

This paper presents a data fusion framework that combines CFD simulations and experimental data through pre-training and fine-tuning to improve hypersonic flow field predictions, enabling more accurate and efficient aerodynamic design.

Contribution

It introduces a novel step-wise approach that leverages pre-training on CFD data and fine-tuning with experimental data, enhancing prediction accuracy and transferability for hypersonic flows.

Findings

Reduced pressure and density errors to 12.6% and 7.4%.

Improved capture of flow features like shocks.

Validated velocity field reconstruction from schlieren images.

Abstract

Accurate prediction of hypersonic flow fields over a compression ramp is critical for aerodynamic design but remains challenging due to the scarcity of experimental measurements such as velocity. This study systematically develops a data fusion framework to address this issue. In the first phase, a model trained solely on Computational Fluid Dynamics (CFD) data establishes a baseline for flow field prediction. The second phase demonstrates that enriching the training with both CFD and experimental data significantly enhances predictive accuracy: errors in pressure and density are reduced to 12.6% and 7.4%, respectively. This model also captures key flow features such as separation and reattachment shocks more distinctly. Physical analyses based on this improved model, including investigations into ramp angle effects and global stability analysis, confirm its utility for efficient design applications. In the third phase, a pre-trained model (using only CFD data) is successfully fine-tuned with experimental schlieren images, effectively reconstructing velocity fields and validating the transferability of the approach. This step-wise methodology demonstrates the effectiveness of combining simulation and experiment by pre-training and fine-tuning, offering a robust and efficient pathway for hypersonic flow modeling in real-world.