01 · SnapshotsEvery converged design becomes a column
Each converged evaluation contributes its whole field on a shared mesh, with run, study fingerprint, solver settings and units attached. Failed and unconverged evaluations stay in the corpus, labelled unusable with their reason, never used to train.
02 · ModesA few modes carry the field
The snapshots are centred and decomposed. The rank is the smallest that keeps 99.9 % of the snapshot energy Method, capped at n − 1 and at 32 modes. The energy left out enters the model’s band.
03 · CoefficientsDesign parameters map to mode weights
A Gaussian process maps design parameters to each mode’s coefficient. The kernel, Matérn 5/2, Matérn 3/2 or squared exponential, is chosen by the closed-form leave-one-out residual over the whole field, never left at a default.
04 · FieldThe whole field, rebuilt for a new design
Predicted coefficients rebuild the full field: the mean plus weighted modes, every node, every quantity, one band per quantity. For flow fields the predicted velocity is projected so that it conserves mass.
05 · ScoreScored the way a sceptic would
Every fold refits basis, rank, kernel and hyperparameters. Near-duplicate designs are held out together, so an infill point cannot borrow accuracy from its twin. The score is judged against a field-error bar fixed before any measurement, and against simpler baselines on the same folds.
06 · Serve or declineServed, refused, or declined, with the reason
If a baseline scores lower on any split, the model is refused for that field, its numbers kept as evidence. Outside its trained region it declines and names the coordinate responsible. What is served stays labelled a prediction until a solver confirms it.