{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp06_four_proposal_generalization60_20260803","cell_id":"catalytic_pathway_enablement__aviation_aeronautics","arm":"COMPLETE_PROPOSAL_PORTFOLIO","candidate_id":"reusable_boundary_layer_transition_cassette","proposal_index":3,"version":0,"title":"Reusable Boundary-Layer Transition Cassette for Subscale Aerodynamic Tests","problem":"At a subscale wind-tunnel test point, an attached boundary layer can remain laminar beyond the location where the experiment requires a prescribed attached turbulent state. Natural transition is feasible, but the model-scale Reynolds number, disturbance environment, surface condition, and available test-section length may leave a substantial activation barrier. The resulting flow state can prevent the test from representing the intended downstream aerodynamic boundary condition. Raising tunnel speed, pressure, density, or model scale may be possible but resource-intensive. The target is not indiscriminate turbulence: it is repeatable transition within a declared surface window without premature separation, excessive disturbance, or undocumented geometry changes.","actors":["Aerodynamicists defining the test boundary conditions","Wind-tunnel test engineers","Wind-tunnel operators","Model designers and fabrication technicians","Boundary-layer instrumentation specialists","Data-quality and configuration-control personnel","Facility safety personnel","Engineers responsible for interpreting or applying the resulting aerodynamic data"],"observable_state":"A smooth subscale model tested at a defined condition shows transition downstream of the declared target window, intermittent transition, or run-to-run location drift. Surface hot-film, temperature-sensitive, acoustic, optical, or other qualified measurements distinguish laminar flow, transition, attached turbulence, and separation. Simultaneous observations include tunnel Reynolds number, Mach number, freestream disturbance, pressure gradient, surface temperature, roughness geometry, cassette contamination or damage, transition spanwise coverage, downstream pressure distribution, vibration, and particle release.","consequence":"The test may fail to establish its required downstream boundary condition, produce data whose interpretation depends on uncontrolled transition location, or require a more resource-intensive facility condition. An excessive or degraded trigger could instead add parasitic drag, cause local separation, shed material, or contaminate measurements beyond the intended transition effect.","affected_objective":"Create a repeatable, documented attached-turbulent boundary condition within a specified location window for subscale aerodynamic testing while preserving model integrity, tunnel safety, downstream measurement validity, and explicit accounting for the trigger's disturbance.","intervention":"Install a removable transition cassette flush with a non-flight wind-tunnel model. The cassette holds a calibrated spanwise array of retained micro-roughness elements at a fixed surface interface. Successive boundary-layer fluid parcels pass over the array, encounter a localized disturbance that lowers the transition threshold, and leave as an attached turbulent boundary layer while the cassette remains in place for reuse. A versioned interface specification limits eligible model geometry, pressure gradient, Reynolds and Mach ranges, surface temperature, alignment, roughness dimensions, and target transition window. Instrumentation verifies transition location, spanwise coverage, attachment, downstream disturbance, and cassette integrity. After a defined exposure or any activity drift, the cassette is removed, cleaned, dimensionally inspected, and requalified against a reference condition; damaged or irrecoverably altered cassettes are retired.","structural_mapping":[{"archetype_element":"Target transformation specification","domain_realization":"Transform an attached laminar boundary layer into an attached turbulent boundary layer within a declared surface-location window under a specified tunnel condition."},{"archetype_element":"Activation barrier","domain_realization":"At model scale, naturally occurring disturbances may be insufficient to initiate and sustain transition within the available surface distance."},{"archetype_element":"Permitted pathway boundary","domain_realization":"The accepted pathway is localized transition followed by attached turbulence; gross separation, particle injection, uncontrolled freestream contamination, or alteration of unrelated model regions is outside scope."},{"archetype_element":"Reusable facilitator","domain_realization":"A retained and removable micro-roughness cassette repeatedly perturbs successive fluid parcels and can serve multiple runs after inspection and restoration."},{"archetype_element":"Facilitator–substrate interface","domain_realization":"The cassette sits flush at a controlled model location, with specified alignment, roughness geometry, pressure gradient, flow state, contact length, sealing, and downstream diagnostic stations."},{"archetype_element":"Selectivity rule","domain_realization":"The cassette must initiate transition in the target boundary layer and location window without triggering separation, excessive spanwise nonuniformity, unacceptable downstream distortion, or disturbance of the opposite surface."},{"archetype_element":"Contact-time or residence window","domain_realization":"Local velocity, roughness length, array spacing, and downstream development distance determine whether the disturbance produces stable attached turbulence before the measurement region."},{"archetype_element":"Turnover capacity","domain_realization":"Qualifying tunnel runs and cumulative flow exposure per cassette are tracked together with transition repeatability, dimensional stability, contamination, and restoration time."},{"archetype_element":"Substrate access condition","domain_realization":"Only test conditions inside the validated Reynolds, Mach, pressure-gradient, surface-temperature, alignment, and freestream-disturbance envelope are eligible."},{"archetype_element":"Saturation and interference monitor","domain_realization":"Transition coverage, downstream attachment, sensor spectra, roughness condition, and run history reveal insufficient disturbance, excessive loading, tunnel interference, or loss of effective activity."},{"archetype_element":"Inhibitor or poison monitor","domain_realization":"Inspection and reference runs detect dust, oil, condensation, erosion, adhesive residue, blocked roughness gaps, surface damage, or sensor faults that suppress or distort the cassette's effect."},{"archetype_element":"Facilitator regeneration cycle","domain_realization":"Remove, clean, inspect, measure, reinstall, align, and requalify the cassette before returning it to ready status."},{"archetype_element":"Byproduct and side-pathway guardrail","domain_realization":"Monitor local separation, excess drag increment, acoustic contamination, vibration, spanwise streaking, particles, model damage, and changes outside the intended measurement region."},{"archetype_element":"Equilibrium neutrality","domain_realization":"The cassette accelerates approach to a turbulent boundary-layer state already feasible at the test condition; it does not make an aerodynamically infeasible model state valid or erase the need to account for the imposed disturbance."},{"archetype_element":"Accountable catalyst steward","domain_realization":"The designated aerodynamic test engineer owns cassette configuration, eligibility, calibration, inspection, capacity, data annotation, regeneration, incident response, and retirement."}],"mechanism_mapping":[{"mechanism_slug":"heterogeneous_catalyst_bed","role":"Immobilizes a calibrated roughness array at a fixed surface interface while successive fluid parcels pass over it, enabling repeated localized transition without releasing the facilitator into the flow.","counterfactual_removal":"Without a retained interface, the disturbance source would require repeated application, could migrate or shed into the tunnel, and would not provide the same separability, inspectability, or regeneration cycle."},{"mechanism_slug":"catalyst_cofactor_system","role":"Maps the Reynolds number, pressure gradient, freestream disturbance, surface temperature, alignment, and downstream development length required for the cassette to produce the target flow state.","counterfactual_removal":"Without the complement map, transition observed at one condition could be attributed to the cassette even though it depended on an unrecorded tunnel or model condition absent in later runs."},{"mechanism_slug":"interface_contract_design","role":"Defines the cassette geometry, mounting preconditions, eligible test envelope, target transition window, downstream measurement boundary, output guarantees, and prohibited interpretations.","counterfactual_removal":"Without the contract, a cassette validated on one model and flow condition could be reused across incompatible pressure gradients, scales, or mounting geometries with false confidence."},{"mechanism_slug":"inhibitor_and_poison_screen","role":"Checks the cassette, model surface, tunnel air, sensors, and mounting interface for contamination, damage, blockage, condensation, or alignment errors before each qualifying run.","counterfactual_removal":"Without screening, a visibly present cassette could lose or distort its transition-triggering activity while operators incorrectly blame the flow condition or accept degraded data."},{"mechanism_slug":"active_site_capacity_dashboard","role":"Displays transition location and coverage, attachment status, run count, cumulative exposure, contamination flags, dimensional inspection status, and restoration state.","counterfactual_removal":"Without joint visibility, operators could continue using a cassette that remains installed but has drifted, or mistake an overloaded test condition for physical degradation."},{"mechanism_slug":"catalyst_regeneration_protocol","role":"Specifies cleaning, dimensional inspection, mounting verification, reference-condition requalification, and thresholds for repair or retirement.","counterfactual_removal":"Without measured restoration, reuse would amount to assuming that a contaminated, eroded, or damaged roughness array remains active because it still looks intact."},{"mechanism_slug":"turnover_and_selectivity_assay","role":"Measures qualifying runs per cassette alongside transition-window success, spanwise uniformity, attachment, downstream effects, degradation, and comparison with a smooth insert.","counterfactual_removal":"Without the assay, an isolated transition event or an unacceptable separation-producing disturbance could be misclassified as useful reusable pathway enablement."},{"mechanism_slug":"small_safe_to_fail_probe","role":"Tests the cassette first on a generic non-flight model at bounded tunnel energy with physical retention, debris protection, predefined stop criteria, and a smooth-insert counterfactual.","counterfactual_removal":"Without a contained probe, shedding, vibration, separation, sensor interference, or ineffective regeneration might first be encountered on a valuable test article or at a higher-risk facility condition."}],"causal_chain":["A subscale model enters a defined test condition with an attached laminar boundary layer persisting beyond the required transition window.","The interface and compatibility checks confirm that model geometry, flow condition, surface state, cassette dimensions, mounting, and diagnostics are inside the validated envelope.","Successive boundary-layer fluid parcels encounter the fixed micro-roughness array for a controlled local contact interval.","The localized disturbance lowers the transition threshold and establishes an intermediate instability pathway without the cassette supplying the bulk energy of the downstream turbulent flow.","The flow releases from the cassette region as an attached turbulent boundary layer and develops before reaching the primary measurement station.","The retained cassette remains available to trigger the same transformation for subsequent fluid parcels and tunnel runs.","Transition location, coverage, attachment, downstream disturbance, particles, and model loads are observed together so raw transition rate cannot conceal an unwanted side pathway.","Run history and reference assays distinguish excessive or incompatible test conditions from cassette contamination, erosion, blockage, or mounting drift.","Cleaning, dimensional inspection, remounting, and reference-condition testing attempt to restore the cassette to its declared ready state.","A cassette that cannot recover transition selectivity, structural integrity, or repeatability is retired; eligible testing reverts to the smooth insert or another approved transition-control method.","Only repeatable target-window transition with bounded downstream effects and multi-cycle recovery supports the catalytic interpretation."],"baseline":"At each evaluated condition, use the same model, tunnel setup, instrumentation, run sequence, and mounting cavity with a dimensionally matched smooth flush insert. Randomize or alternate smooth and active-cassette runs where facility constraints permit. Record natural transition location, attachment, pressure distribution, sensor spectra, tunnel conditions, and repeatability. Include a conventional documented transition device as a reference pathway if already authorized for the rig, but report its geometry and replacement effort separately rather than treating it as a no-facilitator baseline.","nearest_rivals":["Increase tunnel Reynolds number through greater speed, pressure, density, reduced temperature, or model scale; this changes the bulk test condition and facility demand rather than using a small reusable transition interface.","Apply disposable grit, tape, or another renewed roughness treatment before runs; this may trigger transition but requires repeated preparation and may not preserve a measured regeneration and turnover cycle.","Use a permanently integrated model roughness feature; this can impose a fixed transition condition but is not readily separable, regenerable, or replaceable across experimental objectives.","Infer full-scale turbulent behavior through computational modeling or post-test correction; this changes the evidence pathway rather than physically establishing the required boundary-layer state in the experiment.","Accept natural transition and move the measurement region downstream; this redesigns the test geometry or question and may be unavailable within the existing model and test-section boundaries.","Use an active disturbance device such as periodic blowing or excitation; this supplies continuing control energy and introduces a different interface, maintenance burden, and disturbance spectrum."],"remaining_contrastive_claim":"The cassette is catalytic only if a small retained interface repeatedly enables the specified laminar-to-attached-turbulent transformation for successive flow parcels and runs, preserves selectivity, remains separable from the resulting flow, and can be restored to a verified ready state. If performance arises only from increased tunnel energy, a consumed roughness treatment, uncontrolled separation, changed measurement criteria, or untracked facility disturbances, the catalytic explanation fails.","authority_safety":{"decision_authority":"The wind-tunnel facility manager retains authority over tunnel operation and safety. The model owner controls physical modifications. The responsible aerodynamicist approves the experimental boundary condition and interpretation. Any application of resulting data to an aircraft design remains with the applicable design and airworthiness authorities; the cassette steward cannot authorize flight use.","authorized_first_step":"The facility manager and model owner may authorize a low-energy, non-flight probe on a generic instrumented wing-section model with a positively retained cassette, debris protection, remote shutdown, and predeclared flow and structural limits.","excluded_actions":["Installing the cassette or its roughness geometry on a flight vehicle","Testing on a flight-qualified or irreplaceable article during the first probe","Operating outside approved tunnel, model, mounting, or cassette structural limits","Treating triggered transition as natural transition without documenting the imposed boundary condition","Using transition indication alone without checking attachment and downstream side effects","Continuing after particle shedding, insert motion, abnormal vibration, model damage, sensor disagreement, or unexpected separation","Reusing a cassette that has not passed cleaning, dimensional inspection, mounting verification, and reference-condition requalification","Changing eligibility or success thresholds after observing results","Applying results to an untested model geometry, pressure gradient, Reynolds range, or Mach range without additional validation"],"halt_rollback":"Stop the run and return the tunnel to its approved low-energy state upon cassette motion, particle detection, abnormal vibration, unexpected load, local separation outside the allowed region, sensor inconsistency, or model damage. Remove and quarantine the cassette, inspect the model and debris protection, preserve the run configuration and data, and reinstall the smooth flush insert. Resume active-cassette testing only after the facility manager and model owner identify the cause and approve a documented corrective action."},"negative_tests":{"strongest_counterevidence":"Qualified measurements show that natural transition already falls repeatably inside the required window across the target envelope, or that the apparent transition mismatch is caused by sensor interpretation, model-surface defects, tunnel interference, or an incorrectly specified experimental boundary condition. Another strong challenge is that increasing facility condition modestly establishes the target state with fewer side effects and less total burden than maintaining the cassette.","problem_falsifier":"The experiment does not require a prescribed attached-turbulent state, transition location is not causally important to the downstream measurement, the desired state cannot remain attached under the specified condition, or the transition barrier is not repeatable enough to define an eligible substrate and target window.","intervention_falsifier":"Compared with the smooth insert, the cassette does not reproducibly place transition within the predeclared window; produces separation, unacceptable downstream distortion, shedding, vibration, or measurement contamination; works only outside the eligible envelope; degrades before completing repeated cycles; or fails to recover its reference activity and integrity after the regeneration procedure.","risks":["The roughness array could shed particles into the tunnel or damage downstream equipment.","The insert could loosen, vibrate, deform, or disturb the model mounting cavity.","The cassette could cause local separation rather than the intended attached turbulent state.","Transition could be spanwise nonuniform and falsely appear successful at a single sensor location.","Added disturbance could alter pressure, drag, noise, or wake measurements beyond the intended boundary-condition change.","Dust, oil, condensation, erosion, or cleaning residue could change effective roughness.","Sensor placement or processing could misclassify intermittent flow, separation, or tunnel interference as transition.","A surface trigger validated at one pressure gradient or scale could fail under another.","Cleaning could alter micro-roughness dimensions while leaving the cassette visually intact.","High utilization could encourage skipped inspection or requalification.","The imposed transition condition could be omitted from data provenance and later mistaken for natural model behavior.","Successful low-energy results could be extrapolated prematurely to higher Mach number, Reynolds number, load, or valuable test articles."]},"next_evidence_step":"Conduct a bounded low-energy wind-tunnel probe using one generic wing-section model, one smooth flush insert, and three independently measured transition cassettes. Before testing, freeze the target transition window, eligible flow envelope, attachment criteria, downstream-disturbance checks, dimensional tolerances, regeneration procedure, and halt rules. For each cassette, run no more than ten active-cassette exposures interleaved with smooth-insert controls at two predefined test conditions. Measure transition at multiple spanwise and streamwise stations, pressure distribution, attachment, vibration, particle capture, and cassette geometry. Then deliberately apply one approved benign fouling condition, execute one regeneration cycle, and repeat the reference assay. Report specimen-level repeatability, side effects, degradation, and recovered activity without extrapolating to flight or other tunnel regimes.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"Proposal 1 addressed a procedural delay in producing configuration-conformity evidence after avionics replacement. Its facilitator was a governed combination of data contracts, templates, automation, and specialist review, and its output was a packet for an unchanged human release decision. This proposal instead addresses a fluid-mechanical state-transition barrier inside an aerodynamic experiment; its facilitator is a retained surface cassette, its substrates are successive boundary-layer fluid parcels, and its output is an attached turbulent flow state. Proposal 2 addressed chemical ozone conversion in aircraft environmental-control air using an immobilized catalyst cartridge. Although both proposal 2 and this proposal use a fixed interface, their problems, transformations, operating systems, and safety paths are materially different: proposal 2 changes molecular composition for cabin-air quality, whereas this proposal changes boundary-layer stability for test representativeness without intending chemical conversion. Its key controls concern transition location, attachment, disturbance spectra, model integrity, and aerodynamic data provenance rather than ozone selectivity, cabin airflow, reaction byproducts, or aircraft environmental-control integration. The cassette can be tested, adopted, maintained, rejected, and governed independently of both earlier interventions.","revision_record":{"parent_version":null,"progress_targets_addressed":[],"conceptual_changes":[],"operational_changes":[],"evidence_changes":[],"claim_changes":[]}}