{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp12_substrate_denial72_20260805","cell_id":"inversion_of_control__computer_science","arm":"CONSTRAINED_HIGH","candidate_id":"inversion_of_control__computer_science__CONSTRAINED_HIGH","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_HIGH","candidate_id":"inversion_of_control__computer_science__CONSTRAINED_HIGH","proposal_index":1,"version":0,"title":"Heat-Pulled Passive Coolant Allocation for Uneven Server-Rack Loads","problem":"A liquid-cooled computing installation with a shared supply manifold must allocate coolant among racks whose heat loads change independently. Fixed branch restrictions or centrally imposed flow settings require the supply side to anticipate each rack's need; a branch receiving too little coolant during a local load increase can overheat even while cooler branches receive excess flow.","actors":["Heat-producing server rack or cold plate","Shared coolant pump and supply manifold","Passive thermostatic branch valve","Return manifold","Facilities thermal engineer"],"observable_state":"Each branch has an independently observable coolant outlet temperature and flow rate. The problematic state is a hot branch exceeding its allowable outlet-temperature band while another branch remains cooler and continues receiving flow that the hot branch could use.","consequence":"Uneven cooling can cause local processor throttling, protective shutdown, or thermal stress, while indiscriminate increases in total pumping expend energy and may still allocate flow poorly.","affected_objective":"Maintain rack temperatures within their allowable bands under spatially and temporally uneven heat loads while limiting total coolant flow and pump demand.","intervention":"Place a normally restricted, spring-return thermostatic valve in each rack branch. A sealed wax or vapor-pressure actuator thermally coupled to that branch's outlet expands as outlet temperature rises and mechanically opens only that branch's valve; cooling contracts the actuator and reduces its opening. A mechanically maintained manifold pressure supplies the resulting flow. Thus the heat-bearing downstream branch changes its own hydraulic conductance and pulls additional coolant without software, inferred demand, remote commands, or operator scheduling. Mechanical travel stops cap maximum flow, and a passive minimum-flow bypass prevents complete starvation.","structural_mapping":[{"archetype_element":"Usual controller pushing action","domain_realization":"A central pump and fixed or manually balanced restrictions distribute coolant according to anticipated rack demand."},{"archetype_element":"Context holder","domain_realization":"The rack outlet physically contains the most immediate local evidence of insufficient cooling: elevated coolant temperature."},{"archetype_element":"Inverted control boundary","domain_realization":"The branch valve is the boundary at which allocation changes from centrally prescribed branch flow to conductance set by the receiving rack's thermal state."},{"archetype_element":"Activation rule","domain_realization":"Actuator expansion above a chosen physical temperature range overcomes the return spring and increases valve opening."},{"archetype_element":"Interface contract","domain_realization":"The rack may alter only its branch conductance within fixed minimum and maximum valve travel while the shared manifold supplies coolant within a bounded pressure range."},{"archetype_element":"Delegation rule","domain_realization":"Local temperature controls branch opening but cannot alter pump construction, coolant chemistry, other branches, or the mechanical maximum-flow stop."},{"archetype_element":"Feedback signal","domain_realization":"Coolant drawn through the opened branch removes more heat, lowering outlet temperature and mechanically allowing the actuator and spring to reduce the opening."},{"archetype_element":"Fallback and guardrails","domain_realization":"A minimum-flow bypass, maximum-travel stop, pressure relief, and manual isolation valve bound starvation, overdraw, overpressure, and leakage."}],"mechanism_mapping":[{"mechanism_slug":"just_in_time_replenishment_rule","role":"Local thermal demand directly triggers additional physical replenishment of coolant rather than relying on forecasted branch allocation.","counterfactual_removal":"If the temperature-to-valve actuation is removed and the branch opening is fixed, local heat no longer initiates extra coolant flow; the inversion and its allocation effect disappear."},{"mechanism_slug":"feedback","role":"Additional coolant lowers the temperature that opened the valve, forming a local negative thermal-mechanical feedback path.","counterfactual_removal":"If valve opening no longer changes heat removal or the actuator is thermally isolated from the outlet, the branch cannot self-correct its cooling allocation."}],"causal_chain":["A rack's computational load increases its cold-plate heat flux.","Insufficient branch flow raises that rack's coolant outlet temperature.","The local temperature physically expands the thermostatic actuator.","Actuator force opens the rack's branch valve against its spring within mechanical travel limits.","Greater branch conductance draws more coolant from the pressure manifold.","Increased coolant mass flow removes more heat and reduces outlet temperature.","Cooling contracts the actuator, allowing the spring to reduce valve opening and settle the branch near its physical operating band."],"baseline":"A shared constant-pressure coolant loop whose branches use fixed or manually balanced orifices selected for anticipated loads, with no branch-level response to changing local temperature.","nearest_rivals":["Increase uniform pump flow enough to cover the worst-case load at every branch.","Give each rack a dedicated constant-flow pump sized for its maximum load.","Use larger cold plates, heat spreaders, or thermal mass to buffer local temperature excursions.","Manually rebalance fixed branch valves after measuring representative workloads.","Use electronically actuated valves driven by sensors and a software controller."],"remaining_contrastive_claim":"For a two-branch loop with time-varying asymmetric heating and adequate manifold pressure, a branch whose conductance is opened directly by its own outlet temperature should exhibit a lower peak outlet temperature than a fixed-orifice branch at matched aggregate coolant use, specifically because downstream thermal state initiates reallocation. The claim does not extend to cases where actuator lag, insufficient pump head, or strong branch interactions dominate.","authority_safety":{"decision_authority":"A facilities thermal engineer may authorize only a non-production hydraulic bench test and determine pressure, temperature, coolant-compatibility, and electrical-isolation limits.","authorized_first_step":"Construct and test an isolated two-branch low-pressure loop using inert heated cold-plate surrogates, mechanical relief, secondary containment, and de-energized computing hardware.","excluded_actions":["Installation on production computing equipment","Operation above component pressure or temperature ratings","Use of coolant incompatible with seals or nearby electrical systems","Removal or obstruction of pressure relief, minimum-flow bypass, leak containment, or emergency isolation","Treating the passive valve as a substitute for equipment-level overtemperature protection"],"halt_rollback":"Stop heating and isolate the test if leakage, pressure excursion, unstable valve cycling, branch starvation, or temperature-limit approach occurs. Roll back by removing the thermostatic valves and reinstalling the characterized fixed orifices before further testing."},"negative_tests":{"strongest_counterevidence":"At matched aggregate flow, fixed orifices or uniform increased flow keep peak branch temperatures equal to or below those produced by the thermostatic branches across asymmetric load transitions, or the passive branches oscillate or starve one another.","problem_falsifier":"Measurements show that branch outlet temperature does not reliably distinguish local coolant insufficiency from other causes, or that branch loads do not vary independently enough for central allocation mismatch to occur.","intervention_falsifier":"Heating one branch fails to produce a timely, monotonic increase in its valve opening and flow, or the induced flow change fails to reduce that branch's temperature without causing an unacceptable excursion elsewhere.","risks":["Thermal actuator lag may allow damaging temperature overshoot.","Hydraulic coupling may let one hot branch starve neighboring branches.","Valve hysteresis or excessive gain may cause flow and temperature oscillation.","A valve may seize closed, seize open, or drift from its calibrated temperature range.","Added fittings and moving seals introduce leakage and contamination paths.","Coolant near electronics may create corrosion, condensation, or electrical hazards.","A passive local response may conceal inadequate total pump capacity."]},"next_evidence_step":"Run a bounded two-branch benchtop experiment with identical heated cold-plate surrogates. Alternate equal and asymmetric heat inputs while holding coolant, inlet temperature, manifold-pressure condition, and test duration constant. Compare characterized fixed orifices with thermostatic valves, using independent thermocouples, mechanical flow meters, and pressure gauges. Record peak outlet temperature, response time, branch-flow redistribution, aggregate flow, oscillation, and neighbor-branch excursion over a predetermined set of load transitions; do not connect production servers.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"Not assessed because runtime isolation prohibits inspection of other proposals or experiment cells; this candidate is derived only from the supplied archetype and domain card.","revision_record":{"parent_version":null,"progress_targets_addressed":["Construct one causally explicit candidate within the binding substrate constraint.","Preserve inversion-of-control structure in a physical computing-infrastructure problem.","Specify counterfactual independence from forbidden software and governance channels."],"conceptual_changes":["Translated downstream-triggered activation into local thermal-mechanical control of coolant conductance."],"operational_changes":["Bounded the initial intervention to an isolated two-branch bench loop with mechanical safeguards."],"evidence_changes":["Defined matched-condition comparison measurements and explicit problem and intervention falsifiers."],"claim_changes":["Limited the contrastive claim to asymmetric loads, adequate manifold pressure, and matched aggregate coolant use."]},"substrate_contract":{"primary_allowed_process":"PHYSICAL_MATERIAL","counterfactual_independence":"The essential effect survives removal of all software, algorithms, databases, dashboards, reporting, incentives, authorization rules, and procedural enforcement: branch heat expands a material actuator, mechanical displacement opens a valve, hydraulic conductance increases, coolant flow rises, and convective heat removal increases. A person or computer may observe the test, but neither is needed to produce the allocation effect.","forbidden_channel_audit":"No algorithm estimates demand; no sensor report or human decision commands the valve; no software control loop sets flow; and no policy, incentive, workflow, or training step produces the cooling response. Governance appears only in test authorization and safety limits. Measurement instruments evaluate the result but are not in the operative causal path. The pressure source and passive mechanical components alone sustain the intervention."}}}