Stefan Tender | March 2026 | stefan.tender@gmail.com
Physics-Informed Neural Networks (PINNs) solve differential equations by embedding physics directly into neural network training. The fundamental challenge: multi-objective optimization with competing loss terms causes catastrophic training failure on stiff, multi-scale, and high-frequency problems.
This is the single largest obstacle preventing PINNs from replacing classical solvers in production engineering.
A proprietary training enhancement that resolves multi-objective conflicts during PINN training. No architecture changes. No hyperparameter tuning. Drop-in replacement for standard training.
Identical network architecture, optimizer, and training epochs for both Standard and Enhanced. The only difference is the proprietary training enhancement.
| Problem | Standard PINN | Enhanced | Improvement |
|---|---|---|---|
| Poisson Equation (k=5) | Rel L2 = 556% | Rel L2 = 0.22% | 2,483x |
| Poisson Equation (k=10) | Rel L2 = 282% | Rel L2 = 0.04% | 6,883x |
| Robertson Stiff ODE | Rel L2 = 65.4% | Rel L2 = 0.03% | 2,336x |
| 2D Diffusion (a=4, b=4) | Rel L2 = 33.2% | Rel L2 = 0.27% | 122x |
| Problem | Standard PINN | Enhanced | Improvement |
|---|---|---|---|
| Burgers Equation viscous shock, Re~1050 |
Rel L2 = 15.8% | Rel L2 = 0.55% | 28.7x |
| Helmholtz Equation acoustic cavity, k²=60 |
Rel L2 = 67.8% | Rel L2 = 0.77% | 87.8x |
| Category | Problems | Combined Improvement |
|---|---|---|
| Academic (stiff/multi-scale) | 4 | 1,485x |
| Fluid Physics (engineering) | 2 | 50.1x |
| All 6 Benchmarks | 6 | 341x |
The improvement factor is proportional to how severely the problem challenges standard training:
This is by design. Where standard training works reasonably, the gain is moderate. Where it catastrophically fails, the rescue is orders of magnitude. No tuning — the method adapts on its own.
| Application Domain | Impact |
|---|---|
| Computational Fluid Dynamics | Real-time turbulence modeling, aerodynamic optimization — demonstrated on Burgers shock (28.7x) and Helmholtz acoustics (87.8x) |
| Rocket Propulsion | Combustion chemistry ODEs (105 stiffness ratios) — demonstrated on Robertson stiff ODE (2,336x) |
| Battery / Fuel Cell Design | Multi-physics electrochemistry with extreme scale separation |
| Structural Engineering | Crash simulation, fatigue analysis with stiff contact mechanics |
| Climate Modeling | Coupled ocean-atmosphere PDEs with billion-fold timescale gaps |
| Drug Discovery | Pharmacokinetic stiff ODEs with enzyme binding dynamics |
| Semiconductor Design | Multi-scale device simulation (nm to mm) |
Burgers Equation — The canonical benchmark for nonlinear advection-diffusion, forming the mathematical foundation of Navier-Stokes and compressible flow. At low viscosity (Re~1050), a sharp shock develops that standard PINNs smear out entirely. Enhanced captures the shock profile precisely, reducing relative error from 15.8% to 0.55%.
Helmholtz Equation — Models acoustic wave propagation in enclosed cavities (k²=60, approximately 5 wavelengths per dimension). Standard PINNs collapse to a smoothed approximation, missing the wave structure. Enhanced recovers the full oscillatory solution at 0.77% relative error — essential for acoustic design, sonar, and structural vibration analysis.
Provisional patent filed. Full technical details available under NDA.
of everything I have built
What you see above — solving differential equations — is one application of a deeper principle. The same principle produces validated results across entirely different domains:
The full picture is much larger. I will share it once we establish collaboration terms.