==================== COMPARISON: 0d_case vs flame_speed ====================

| Aspect                | 0d_case                                   | flame_speed                              |
|-----------------------|-------------------------------------------|------------------------------------------|
| Solver                | chemFoam (0D homogeneous reactor)         | reactingFoam (1D reacting flow)          |
| Goal                  | Ignition Delay Time (IDT)                 | Laminar Flame Speed                      |
| Mesh                  | Single cell (none)                        | 1000 x 1 x 1 (1D, 1 m long)              |
| Initial Temperature   | 900 K                                     | 443 K unburnt / 1200 K ignition patch    |
| Initial Pressure      | 607,950 Pa (~6 atm)                       | 101,325 Pa (1 atm, outlet)               |
| Equivalence Ratio     | 0.5 (lean)                                | ~1.0 (rich, fuel/air mass ratio 0.06)    |
| Fuel Components       | C10H22, IC8H18, MCH, C2H5OH               | C10H22, C8H18, MCH, C7H8                 |
| Oxidiser              | Air (O2 + N2)                             | Air (O2 + N2)                            |
| Time Range            | 0 - 0.025 s                               | 0 - 0.5 s                                |
| Time Step             | 1e-7 (adjustable, max 1e-3)               | 5e-7 (adjustable, maxCo 0.05)            |
| ODE Solver            | seulex                                    | rodas23                                  |
| Chemistry absTol      | 1e-14                                     | 1e-8                                     |
| Chemistry relTol      | 0.1                                       | 0.0001                                   |
| Mechanism             | 70-species skeletal (same in both cases)  | 70-species skeletal (same in both cases) |
| Execution             | Serial only                               | Serial only                              |
| Autoignition Init     | Chemistry-driven autoignition             | Box-to-cell ignition patch (0-2 cm)      |
| Boundary Conditions   | N/A (0D reactor)                          | Inlet: fixedValue U; Outlet: totalPressure|

Note: The two cases differ in fuel composition and operating conditions, reflecting
different validation targets (IDT vs laminar flame speed) from the same skeletal mechanism.
