{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp12_substrate_denial72_20260805","cell_id":"inversion_of_control__computer_science","arm":"CONSTRAINED_MAX","candidate_id":"inversion_of_control__computer_science__CONSTRAINED_MAX","decision":"PROPOSAL","abstention_reason":null,"proposal":{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp12_substrate_denial72_20260805","cell_id":"inversion_of_control__computer_science","arm":"CONSTRAINED_MAX","candidate_id":"inversion_of_control__computer_science__CONSTRAINED_MAX","proposal_index":1,"version":0,"title":"Cold-Plate-Triggered Passive Coolant Pull for Heterogeneous Compute Nodes","problem":"A shared liquid-cooling loop in a heterogeneous compute node has a bounded coolant-flow budget while processors and accelerators generate independent heat transients. Fixed branch restrictions allocate flow from nominal conditions, so the upstream manifold cannot respond to which cold plate physically needs flow at a given moment. The diagnostic problem is a hot or rapidly heating branch coexisting with cool branches that continue receiving coolant.","actors":["Heat-generating processor or accelerator packages","Branch cold plates containing the local thermal state","Coolant branches, supply-and-return manifold, and direct-wired fixed-speed pump","Passive wax-expansion valve cartridges and spring linkages","Laboratory thermal-safety engineer"],"observable_state":"For each branch, observe cold-plate temperature, valve stroke, coolant flow, and inlet-to-outlet coolant temperature, together with manifold differential pressure, pump power, and leak status. Evidence of the problem is one plate approaching its declared thermal ceiling while another remains cool and receives flow, without exhaustion of the loop's total flow and pressure envelope.","consequence":"With fixed allocation, a branch can exceed its thermal ceiling even while coolant capacity is spent on cooler branches. Increasing uniform flow can compensate but raises the required pumping burden rather than correcting branch-level allocation.","affected_objective":"Minimize the highest cold-plate temperature and temperature-time above a declared target within a fixed coolant-flow budget, while preserving pressure, leakage, and material-compatibility limits.","intervention":"Insert a passive thermomechanical valve at each cold-plate inlet. A conductive boss on the plate heats a sealed wax-expansion actuator that mechanically opens a spool valve as plate temperature rises; a spring reduces the aperture as the plate cools. Opening lowers that branch's hydraulic resistance, allowing its local thermal state to draw more of the common coolant flow. Each branch retains a fixed minimum-flow bypass and a mechanical maximum-opening stop, while the loop uses mechanical pressure relief and containment. No electronic sensor, processor, forecast, or software controller participates in branch actuation.","structural_mapping":[{"archetype_element":"usual_controller_pushes_action","domain_realization":"A pump and fixed restrictors continuously push a preset branch-flow allocation regardless of each cold plate's current thermal state."},{"archetype_element":"inverted_control_boundary","domain_realization":"At each cold-plate inlet, the upstream system supplies only a bounded hydraulic envelope; the downstream plate's material temperature controls the branch aperture."},{"archetype_element":"context_holder","domain_realization":"The cold-plate metal physically embodies the branch-local heat state relevant to immediate cooling demand."},{"archetype_element":"activation_rule","domain_realization":"Temperature-driven wax expansion moves the valve toward open across a calibrated transition interval; cooling permits spring return toward the minimum-flow position."},{"archetype_element":"interface_contract","domain_realization":"The cartridge exposes a bounded aperture range and specified coolant, temperature, pressure, stroke, and thermal-coupling limits without access to pump control or other branches."},{"archetype_element":"delegation_rule","domain_realization":"A branch may vary only its own hydraulic resistance between physical stops; it cannot change loop pressure limits or directly command peer branches."},{"archetype_element":"pull_rule","domain_realization":"A hotter plate opens its inlet, lowers local resistance, and draws a larger share of available flow; cooler plates remain near their bypass flow."},{"archetype_element":"feedback_signal","domain_realization":"Additional convection cools the plate and wax actuator, permitting the spring to narrow the valve and close the physical negative-feedback loop."},{"archetype_element":"guardrail_policy","domain_realization":"Minimum-flow bypasses, maximum-stroke stops, mechanical pressure relief, hardwired heater cutoffs, and leak containment bound failure without runtime computation."},{"archetype_element":"override_or_fallback_path","domain_realization":"A cartridge can be mechanically locked open or replaced by the original fixed restrictor, restoring the baseline hydraulic configuration."}],"mechanism_mapping":[{"mechanism_slug":"kanban_pull_system","role":"Downstream thermal demand supplies the physical pull signal: the cold plate itself opens the path that admits upstream coolant rather than waiting for a scheduled allocation.","counterfactual_removal":"Locking every cartridge at a nominal aperture restores push allocation. Cooling continues, but local demand can no longer initiate additional branch flow, so the inversion disappears."},{"mechanism_slug":"just_in_time_replenishment_rule","role":"Coolant admission changes when and where thermal headroom is being consumed, through direct temperature-to-stroke coupling.","counterfactual_removal":"Thermally decoupling the wax actuator from its plate makes aperture insensitive to local heat. Any remaining flow change is then caused by common manifold conditions, not need-timed replenishment."}],"causal_chain":["Independent device heat loads create unequal cold-plate temperatures.","Heat conducts from a warmer plate into its mechanically linked wax actuator.","Wax expansion moves the spool valve toward a larger aperture.","The branch's hydraulic resistance falls, increasing its share of coolant flow under the common pressure gradient.","Greater coolant flow increases convective heat removal from that plate.","Cooling contracts the actuator and permits spring return, reducing flow as local need recedes.","Branch-local material state therefore initiates coolant allocation while the upstream pump supplies only the bounded resource envelope."],"baseline":"Use the identical loop and cartridges mechanically locked at calibrated nominal apertures, making them equivalent to fixed restrictors. Hold coolant, inlet temperature, heater traces, total-flow setting, pump-energy accounting, and safety protections constant so the comparison isolates temperature-to-aperture actuation.","nearest_rivals":["Fixed restrictors with higher uniform total flow: simple and predictable, but address a hot branch by increasing flow through every branch.","Per-branch electronic temperature sensors, motorized valves, and a centralized feedback controller: potentially more tunable, but the operative allocation depends on sensing, computation, and software control.","A shared passive return-temperature thermostat that changes total loop flow: computation-free, but aggregate temperature rather than each downstream branch initiates the response.","Pressure-compensating branch valves: stabilize preset flows against manifold changes but do not make flow respond to local thermal demand.","Heat pipes, vapor chambers, or added thermal mass: redistribute or buffer heat without reallocating the shared coolant resource."],"remaining_contrastive_claim":"The bounded hypothesis, not a novelty claim, is that under identical heater traces and coolant conditions, active thermomechanical cartridges will produce a branch-local monotonic temperature-to-aperture-to-flow response and reduce worst-plate thermal exposure relative to the same cartridges locked at fixed aperture, with pump energy accounted for. The response must persist when all logging and control computation is disconnected; superiority to an optimized electronic controller is not claimed.","authority_safety":{"decision_authority":"A qualified laboratory thermal and hardware-safety engineer may authorize only the non-production dummy-load experiment. Any powered-computer deployment remains subject to the equipment owner's and manufacturer's separate authority.","authorized_first_step":"Fabricate removable cartridges and test them on a low-pressure, three-branch closed loop using electrically heated dummy cold plates, nonconductive surroundings, mechanical relief, containment, and independent hardwired temperature cutoffs.","excluded_actions":["Installation in a production or occupied compute system","Connection to live silicon during the first evidence step","Disabling manufacturer thermal shutdowns, pressure relief, grounding, or leak detection","Exceeding declared pressure, temperature, electrical, or coolant-compatibility limits","Using an experimental coolant chemistry without material-compatibility testing","Allowing measurement software to command the valves or pump"],"halt_rollback":"Cut heater power and stop the pump upon leakage, pressure-limit violation, valve chatter, loss of minimum flow, or any plate reaching its predeclared cutoff. Isolate and drain the test section, inspect containment, and restore fixed restrictors before any restart."},"negative_tests":{"strongest_counterevidence":"Directly heating one plate fails to increase only its valve stroke and branch flow, actuator delay makes its peak temperature worse, or locked fixed restrictors provide equal or better worst-plate thermal exposure at the same flow and pump-energy envelope.","problem_falsifier":"Across the predeclared independent heater traces, branch thermal needs do not diverge, fixed flow already keeps every plate within bounds without avoidable flow to cool branches, or only aggregate loop state predicts required cooling. Any of these removes the asserted mismatch between upstream allocation and branch-local context.","intervention_falsifier":"The cartridge shows no temperature-to-flow increase beyond measurement uncertainty, responds only after the plate reaches its cutoff, fails to improve the paired thermal metric against locked cartridges, or violates pressure, leakage, stability, or minimum-flow limits.","risks":["Wax-actuator lag, hysteresis, stiction, fatigue, or calibration drift could miss short heat transients.","Opening one branch could depress manifold pressure and starve another branch during combined loads.","A stuck-closed valve or undersized bypass could overheat a device; a stuck-open valve could consume excessive flow.","Added seals and joints introduce leakage, corrosion, coolant-contamination, and electrical-hazard paths.","The actuator coupling point may not represent the hottest die region because of package and interface thermal resistance.","Valve chatter, hydraulic oscillation, cavitation, or pressure spikes could destabilize the loop.","The intervention reallocates existing cooling capacity and cannot remedy an insufficient total heat-rejection capacity."]},"next_evidence_step":"Run a bounded 12-run bench crossover: six predeclared 15-minute heater traces, each executed once with the cartridges active and once with them mechanically locked at nominal aperture, in counterbalanced order. Use three aluminum dummy cold plates, a direct-wired fixed-speed pump, and mechanical relief. Independent thermocouples, valve-stroke gauges, branch flow meters, pressure transducers, and a wattmeter may log observations but must have no actuation connection. Test whether local temperature precedes a flow increase beyond measurement uncertainty and compare peak and temperature-time-above-target metrics with pump energy accounted for. Stop after these runs and before testing live silicon.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"No other proposal or experiment candidate was inspected, so cross-proposal diversity is not asserted. This candidate is characterized internally by its passive thermohydraulic intervention in computing hardware rather than a software, reporting, or governance mechanism.","revision_record":{"parent_version":null,"progress_targets_addressed":["Constructed an initial candidate satisfying the physical-substrate counterfactual","Preserved the reversal from upstream push allocation to downstream branch activation","Specified physical guardrails, serious rivals, falsifiers, and a bounded dummy-load test"],"conceptual_changes":["Initial version; no parent. The archetype is realized as local thermal state controlling material coolant flow."],"operational_changes":["Initial version; defined wax-actuated spool valves, minimum-flow bypasses, maximum stops, relief, and a fixed-restrictor rollback."],"evidence_changes":["Initial version; defined a 12-run paired bench crossover with log-only instrumentation."],"claim_changes":["Initial version; limited the claim to a falsifiable mechanistic and thermal comparison without novelty, prevalence, demand, or effect-size assertions."]},"substrate_contract":{"primary_allowed_process":"PHYSICAL_MATERIAL","counterfactual_independence":"With an exogenous heat load and pump energy maintained, remove every computer, firmware component, algorithm, database, dashboard, report, incentive, permission check, and operating procedure. Heat still conducts into the wax, expansion still moves the spool, hydraulic resistance still falls, coolant still flows, and convection still cools the plate. Removing the evaluation sensors also leaves this causal sequence intact.","forbidden_channel_audit":"No software or algorithm infers demand or selects branch flow. Logging and reporting are optional evaluation wrappers with no actuator connection. Authorization and procedures only bound the experiment and do not trigger cooling events. Thermocouples and flow meters are observational; operative sensing is direct material expansion mechanically linked to the valve. No human response is required after energizing the loop. The pump operates at a fixed physical setting with mechanical relief, so the essential control loop is thermomechanical and hydraulic rather than computational."}}}