Remove incorrect effectiveness from discretized HX#74
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The per-segment effectiveness calculation produced incorrect results for variable-property fluids. Effectiveness decreased as segment count increased — the opposite of what the doc comments claimed — because the per-segment C_min sum cherry-picks the minimum stream independently per segment, inflating q_max for fluids where C_min flips between streams. Rather than replace the calculation with a correct but expensive iterative approach, remove it entirely. Consumers who need effectiveness can compute it externally using RecuperatorGivenOutlet to find the outlet temperature where min_delta_t = 0. Closes #73
gdtroszak
approved these changes
Mar 5, 2026
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Removes the
Effectivenesstype and computation from the discretized heat exchanger.The per-segment effectiveness calculation was incorrect for variable-property fluids (#73). It picked
C_minindependently per segment, so for fluids like sCO₂ near the critical point whereC_minflips between streams, more segments produced a largerq_maxdenominator and lower effectiveness — diverging instead of converging. The doc comments claimed the opposite.This is a breaking change to
Results,RecuperatorGivenUaOutput, andRecuperatorGivenOutletOutput. Consumers who need effectiveness can compute it externally by finding the outlet temperature wheremin_delta_t = 0usingRecuperatorGivenOutlet, as described in the issue.Closes #73