Aero
Live contract
Closed identities in aero/MEANLINE.md. Euler work is the shaft work. Do not export CFD from the old station table.
- Δh0 Euler
- 40.42 kJ/kg
- U2
- 201.06 m/s
- C2
- 208.14 m/s
- Cθ2
- 201.06 m/s
- Cm2
- 53.86 m/s
- Cθ3
- 0
- CFD target (item 6)
- Δh0 40.4 kJ/kg · dump P 13.89 MPa
- PR
- 1.8
- α2
- 75°
- M2
- 0.43
- 75.9 kJ/kg
- dead bookkeeping (η_ts×101)
- 61 kJ/kg
- static h2−h3, mis-labeled Δh0
- η_tt 0.802 / η_ts 0.75
- UNSIGNED
U2 Cθ2 − U3 Cθ3 = U2² at Cθ3 = 0. With |C3| ≤ 120, extra swirl adds at most 9.05 kJ/kg → Δh0 ≤ 49.47. 75.9 is incompatible (would need Cθ3 ≈ −474 m/s). Station-derived 0.746 travels with the UNSIGNED η labels on the old 101×0.75 bookkeeping.
Frozen mixing-plane +56.5 vs Euler Δh0 40.4 — swirl-high because the 2D dump still carries swirl (C_out 266). That is a 2D-exducer miss (Japikse: exit is axial), not a 75.9 fail and not a 61 miss. 61 is the old mis-labeled static drop, not the freeze comparator. Do not recut 13 / 0.40 / Ø48 to hit 75.9. Chip 6 stays OPEN.
Named enthalpies (totals vs static)
| h kJ/kg | note | |
|---|---|---|
| h00 nozzle ID | ≈ 1158 | P0 = 25.00 MPa, T0 = 650 C, C≈30 |
| h02 = h00 | ≈ 1158 | adiabatic nozzle |
| h2 static rotor in | ≈ 1136 | ke2 = C2²/2 = 21.66 |
| h03 | ≈ 1117.6 | h02 − 40.42 |
| h3 static dump-in | ≈ 1110.4 | ke3 = 120²/2 = 7.20 — not 1075 |
ṁ is unsigned until a 3D gallery exists. 2D pitch mass is not ring ṁ.
Old table (do not export CFD from this)
| Station | P static (MPa) | T static (°C) | C (m/s) | P0 (MPa) | h (kJ/kg) | what was wrong |
|---|---|---|---|---|---|---|
| 1 inlet | 25.0 | 650 | 30 | 25.00 | 1157.9 | totals 25.00/650 — OK |
| 2 noz TE | 22.19 | 632 | 208 | 25.00 | 1136.3 | static; totals OK |
| 3 rot in | 22.19 | 632 | 208 | 25.00 | 1136.3 | static; totals were 25.00/650 — OK |
| 4 rot ex | 13.89 | 579 | 120 | 14.51 | 1075.0 | static forced from fake Δh0=75.9 |
| 5 dump | 13.89 | 585 | 40 | 13.96 | 1082.2 | mixed static/total |
Loss register
| Term | pts of Δhs |
|---|---|
| incidence | 1 |
| passage | 8 |
| TE | 2.5 |
| tip Japikse | 4.8 |
| windage | 1 |
| sum | 17.3 pts |
| η_ts if sum | 0.827 |
A budget, not a CFD result and not a closed efficiency. Futral tip would be 7.6 pts, not used.
Velocity triangles
| r | U (m/s) | C (m/s) | W (m/s) | ||
|---|---|---|---|---|---|
| rotor inlet | 24.00 mm | 201.06 | 208.14 | 53.86 | Cθ2 = U2 · α2 75° · M2 0.43 |
| rotor exit | 9.00 mm | 75.40 | 120 | 142 | Cθ3 = 0 · C3=120 labeled dump-in |
Contract: Cθ3 = 0 (axial/radial dump, no swirl). Frozen C_out 266 is 2D-dump swirl, not a triangle miss.
ROSS 2.3 undamped
Foil 1e6–5e6 crosses a critical before 80k. First pair 26.4k at 1e6. Need k ≳ 5e7 for 80k. 1st pair 26.4 krpm at k=1e6, ~80 krpm at 1e7, AMB needs ≥5e7. J2 foil can ends Z=71.00, disk 72–76.
