Models. Optuna-tuned MLPs (40 trials each). MF = frozen LF surrogate f
L(x) + HF correction net g([x, f
L]) with residual skip.
| HF-test R² | CL | CD | CM |
| LF-only | 0.933 | 0.953 | 0.932 |
| HF-only | 0.907 | 0.917 | 0.840 |
| MF | 0.953 | 0.949 | 0.927 |
Surrogate predictions, not CFD. Accuracy drops outside the sampled design space and in regions where CFD often failed (high sweep with high AR).