HyFlux Extensions#

Capabilities beyond the CASCADE parity perimeter. These are HyFlux-originated workstreams — they cite CASCADE data where disclosed but make no parity claim.

Superconducting LH₂ + SC propulsion analysis#

Source: src/engine/cascade.ts:computeLCA (scAnalysis), src/engine/fuel-costs.ts:q5Renormalisation Test evidence: tests/fuel-costs.spec.ts, tests/cascade-parity.spec.ts

The superconducting (HTS) motor lever sc (%) scales delivered LH₂ CI by \((1 - sc/100)\) and reports an analysis block: power density 5.2 kW/kg conventional vs 25–35 kW/kg HTS, “free” cryogenic cooling from the LH₂ sink, and programme anchors (Airbus ASCEND 500 kW demo, RTX/Pratt 260 kW → 2.5 MW, Hinetics MW-class). In the cost model the fuel-cell + SC chain converts fuel to shaft at η = 0.55 vs 0.40 for turbines — enough to invert the methane-vs-hydrogen cost ranking per unit of propulsive output (see Costs).

Airport infrastructure map groundwork#

Source: src/map/ (geodesic.ts, demand.ts, airports.ts, provider.ts, AirportMap.tsx) Test evidence: tests/geodesic.spec.ts, tests/airport-demand.spec.ts

Phase 5 scaffold (DL-031/DL-035): a MapLibre-first airport comparison map behind a provider abstraction (token-free default tiles, zero recurring cost per DL-011), with all geometry computed geodesically — haversine distance, direct-geodesic destination points, Chamberlain–Duquette spherical polygon area; never from screen pixels (Web-Mercator pixel areas are latitude-distorted). Six airport archetypes (LHR, AMS, INV, SIN, DXB, MEM) and a demand-driven sizing model (peak-day/peak-hour factors, reserve-days storage, tank counts, truck movements with a pipeline threshold) carry a standing CONCEPTUAL — NOT VALIDATED label: every constant is named, editable and literature-approximate, and the outputs must not be used for design, safety or cost decisions.

Usable-fuel pathways (Workstream A)#

Source: src/engine/fuel-pathways.ts:usableFuel, reproduceBoeingUsableFuel Test evidence: tests/usable-fuel.spec.ts

An independent first-principles chain model: usable fuel = fuel energy delivered to the aircraft (LHV) ÷ primary input energy, with per-stage retentions and overheads,

\[\text{usable} = \frac{\prod_i r_i}{\text{baseInput} + \sum_j o_j}\]

evaluated at central, all-pessimistic and all-optimistic stage values. Boeing’s published chart values (claim register BC-01…BC-05) fall inside the independent envelopes for all five pathways — bio-CH₄ 54.3 % vs 54 %, e-CH₄ 48.1 % vs 43 % (claim digitised/unverified), LH₂ 44.8 % vs 38 % (Boeing pessimistic-side), bio-SAF 30.2 % vs 30 %, e-SAF 23.8 % vs 22 % — all classified Conditionally validated since Boeing discloses no stage assumptions. Key boundary finding: e-SAF’s 22 % is only reproducible when non-jet Fischer–Tropsch co-products are treated as losses (no energy allocation); with co-product credit the chain stays above 28 %. Boeing’s implicit boundary choice is undisclosed (WorkstreamA-UsableFuel-Report).

Pulse curve#

Source: src/engine/curves.ts:pulseAt, buildPulseSeries Test evidence: tests/pulse-curve.spec.ts

The CASCADE custom “pulse” curve (cf. CASCADE Operations, Custom Curves → Pulse), implemented exactly from its published formulation (DL-020): two concatenated sigmoids

\[\begin{split}y(t) = \begin{cases} 0 & t \le t_0 \\ A_{peak}\, S\!\left(\frac{t - t_0}{t_{peak} - t_0}\right) & t_0 < t \le t_{peak} \\ A_{peak} + (A_f - A_{peak})\, S\!\left(\frac{t - t_{peak}} {t_f - t_{peak}}\right) & t_{peak} < t \le t_f \\ A_f & t > t_f \end{cases}, \qquad S(t') = \frac{1}{1 + \left(\frac{t'}{1 - t'}\right)^{-a}}\end{split}\]

with exact value \(A_{peak}\) at \(t_{peak}\), \(A_f\) held beyond \(t_f\), and zero-slope knots for \(a > 1\). Eleven tests cover monotonicity, half-amplitude midpoints, continuity at all knots, zero-duration edges and shape-parameter behaviour. UI exposure remains deferred: the shared CurveEditor param model (shape, entry/end years and values, slope, inflection year, custom points) does not map onto the pulse parameter set, and no approximate mapping is offered (see Aircraft — Fleet Renewal & Future Aircraft).

LH₂ CI-driven accounting view (lh2_ci_driven)#

Source: src/engine/cascade.ts:computeLCA (lh2CiDriven, deliveredLH2CIAt, lh2LedgerSharePct) Test evidence: tests/lh2-energy-ledger.spec.ts, tests/cascade-measured-lh2.spec.ts

An opt-in HyFlux accounting view (default off, bit-identical when off): the LH₂-attributable share of the aircraft wedge (the sc × 0.5 term) is re-attributed to the energy wedge as a CI-driven term of the same form SAF and methane use, so LH₂ abatement tracks the delivered carbon intensity — and becomes a visible penalty on slow-decarbonising grids. lh2_ledger is accepted as a deprecated alias (DL-142) and is not URL-serialisable.

This is not CASCADE’s method. A live orchestrationLayerInterface capture (2026-08-01) measured that CASCADE books LH₂ aircraft abatement wholly in the Aircraft wedge, applies delivered-LH₂ CI inside the Aircraft module, and prevents double counting by sequential activity removal — hydrogen aircraft shrink the residual Jet-A pool that the later Operations and Energy stages receive; there is no Energy-wedge LH₂ term and no explicit de-duplication subtraction (see Methodology Parity, “Measured CASCADE LH₂ wedge accounting”). The engine therefore refuses the combination: enabling this view under evidence_basis: 'CASCADE_PARITY' throws, and no library preset sets the flag. UI surfaces label it “HyFlux CI-driven LH₂ accounting view — experimental HyFlux analysis; CASCADE parity uses sequential Aircraft-stage LH₂ accounting instead.”

Known deviations / limitations#

  • SC analysis constants (power densities, programme powers) are literature anchors, not validated product data.

  • Airport sizing is explicitly conceptual; no geocoded demand data yet.

  • Usable-fuel stage values are literature-approximate envelopes, not calibrated plant data; the e-methane Boeing value remains unverified pending chart digitisation (DL-008).

  • Pulse curve is engine-level only (CurveEditor param-model mismatch, documented under Aircraft — Fleet Renewal & Future Aircraft).