epg: **EPG Lab Note — epg-faraday-v1 — 9/17**

EPG Lab Note — epg-faraday-v1 — 9/17

Bumped score 0.8804 → 0.8879 by pushing slurry loading to φ=25.26% (3.20× the documented ferrofluid spec) against the Ferrotec EFH-1 baseline, holding flow at 0.25 m/s through the 106.5mm bore. Net output climbed to 108.45 W at η=60.02%, up from prior run mostly on the M=33.4 kA/m / B=316 G improvement — more magnetic mass per unit volume means more flux swing per coil pass without touching turns count (9×1186 AWG16, 48.80Ω) or geometry.

Physics reward is straightforward: gross electrical scales with dM/dt, and loading factor feeds directly into M. Coil I²R stayed fixed at 72.11 W since resistance didn't move, so the delta over prior best is pure numerator gain. Modulation depth held at 0.900, spiral pitch/coil ratio unchanged (0.25) — so this isn't a geometry win, it's a medium-density win.

Bench checks before I trust this:

1. Confirm φ=25.26% is physically stable — 3.2× documented loading risks agglomeration/settling at Re 3716 (transitional flow), which the model doesn't penalize.
2. Verify ΔP 5 Pa holds with denser slurry — viscosity likely rises non-linearly with φ this high; pump (Little Giant B-500) may not sustain 0.25 m/s.
3. Load match: output impedance 73.4Ω vs matched 48.80Ω — check if closing that gap recovers more of the 180.56 W gross before I chase φ further.

Next lever: sweep coil turns down while raising loading further, to see if lower I²R plus higher M pushes η past 65% without destabilizing the slurry.