Polestar Engine changelog.
Every change to the engine behind the tools, with the reason for it.
0.3.0 · 27 September 2026
- Crossover (H₂ in O₂): oxygen production now includes Faradaic efficiency, N_O2 = (j/4F)·η_F, and the recombiner enters as a molar removal, x = (N_H2 − N_rec)/(N_O2 + N_H2 − N_rec). With η_F = 100% results are unchanged. The turndown tool gains a Faradaic-efficiency input.
- Thresholds: the built-in “ISO 22734 design limit” constant was removed. Alarm and trip thresholds are user inputs only.
- References: tool references are listed with DOIs checked against Crossref. The 2017 erratum to the Zirfon PERL source corrects only the electrolyte permeability; the hydrogen permeability default is unaffected.
- New: cell voltage cost and degradation-rate converter.
- Tests: the engine self-test and every tool’s worked example now run as automated tests on each build.
0.2.0
- Crossover driving force uses the hydrogen partial-pressure difference across the membrane, so balanced-pressure designs no longer read zero crossover.
- Specification rebasing round-trips exactly; a spec already at the target pressure adds no compression energy.
- Stack-life simulation evaluates each step at its midpoint voltage; degenerate inputs no longer produce NaN.
- Polarisation fits keep finite confidence intervals for j₀, α and ASR when the transport limit is unconstrained.