Axial turbine

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Input file

# Axial turbine
#
# A repeating-stage axial turbine with two blade rows.

# New working directory for each invocation
workdir: runs/*

# Perfect gas inlet reprensentative of a gas turbine
inlet:
  Po: 16.0e5
  To: 1600.
  cp: 1100.
  gamma: 1.33

# Set viscosity by vane Reynolds number
Re_surf: 5e5

# Design variables for an axial turbine
mean_line:
  type: axial_turbine
  # Duty
  mdot: 500.
  rrms: 1.0
  # Aerodynamics
  psi: 1.6
  phi2: 0.6
  Ma2: 0.7
  fac_Ma3_rel: 1.0
  zeta: [1.0, 1.0]
  # Guess of loss
  Ys: [0.02, 0.05]

# Prescribe the dimensional chords
annulus:
  type: fixed_axial_chord
  cx_gap: [0.1, 0.06, 0.1]
  cx_row: [0.1, 0.1]

# Coarse H-mesh
mesh:
  type: h
  yplus: 30.0
  resolution_factor: 0.5

# Define one mid-span section in stator and rotor
blades:
    - spf: 0.5
      thick: [0.04, 0.12, 0.35, 0.2, 0.0, 0.15]
      camber: [0., 0., 0.0]
      theta_offset: 0.1
    - spf: 0.5
      thick: [0.04, 0.12, 0.35, 0.2, 0.0, 0.15]
      camber: [0., 0., 0.0]

# Circulation coefficient to set blade loadings
nblade:
  - Co: 0.6
  - Co: 0.6

# Configure the RANS solver
solver:
  type: ember
  n_step: 2000
  n_step_avg: 1000
  # smooth2_adapt: 0.5

# Configure iterative updates of the geometry
iterate:
  # Make the mean-line loss match CFD
  mean_line:
    tolerance:
      Ys: 0.01
  # Correct for deviation using trailing-edge recamber
  deviation:
  # Correct for incidence using leading-edge recamber
  incidence:

# Additional plots to produce
post_process:
  # Loss at stator and rotor exits
  # Non-dimensional meridional coordinate m is defined:
  #   m=0 at inlet
  #   m=1 at stator LE
  #   m=2 at stator TE,
  #   m=3 at rotor LE
  #   m=4 at rotor TE
  #   m=5 at exit
  - type: contour
    coord: m
    value: [2.48, 2.52]
    variable: Alpha
  - type: contour
    coord: m
    value: [2.48, 2.52]
    variable: Cho
  - type: contour
    coord: m
    value: [2.48, 2.52]
    variable: Ys
  # Mid-span Mach
  - type: contour
    coord: spf
    value: 0.5
    variable: Ma_rel

Log output

*** TURBIGEN v2.7.3 ***
Starting at 2026-02-04T22:58:23
Working directory: /builds/jb753/turbigen/runs/0000
Iterating for max 20 iterations...
  Min Inc[0] DInc[0] Inc[1] DInc[1] Dev[0] DDev[0] Dev[1] DDev[1] Ys[0] DYs[0] Ys[1] DYs[1]
-------------------------------------------------------------------------------------------
 2.31  -69.8      -2   67.3       2  0.562   -0.56  -0.37   0.373 0.024  0.002 0.049  -0.00
 2.31  -66.1      -2   63.4       2  -0.09   0.097  0.172   -0.17 0.025  0.001 0.052  0.001
 2.32  -62.1      -2   30.3    1.51  -0.11   0.117  0.093   -0.09 0.025  0.000 0.051  0.000
 2.34  -31.9   -1.59   25.5    1.27  -0.11   0.117  0.086   -0.08 0.025  0.000 0.051  -0.00
 2.33  -26.8   -1.34   21.5    1.07  -0.09   0.090  0.074   -0.07 0.024  -3.53 0.050  -0.00
  Min Inc[0] DInc[0] Inc[1] DInc[1] Dev[0] DDev[0] Dev[1] DDev[1] Ys[0] DYs[0] Ys[1] DYs[1]
-------------------------------------------------------------------------------------------
 2.33   11.6    0.58  -17.7   -0.88  -0.07   0.078  0.064   -0.06 0.024  -0.00 0.050  -0.00
Finished iterating, converged=True.
   Variable  Nominal  Actual   Err_abs  Err_rel/%
-------------------------------------------------
        Ma2      0.7   0.697    0.0032        0.5
      Ys[0]   0.0247  0.0245   0.00013       0.53
      Ys[1]   0.0506  0.0502   0.00033       0.65
fac_Ma3_rel        1   0.998    0.0017        0.2
       mdot      500     500     -0.46       -0.1
       phi2      0.6   0.601    -0.001       -0.2
        psi      1.6    1.59    0.0084        0.5
       rrms        1       1         0        0.0
    zeta[0]        1       1  -2.7e-05    -0.0027
    zeta[1]        1   0.998    0.0025       0.25
      PR_ts              1.8
      PR_tt             1.67
    Ma3_rel            0.698
     Alpha1            -24.6
        Lam            0.525
       htr2            0.876
     eta_tt            0.939
     eta_ts            0.833
      Omega              353
Efficiency/%: eta_tt=93.9, eta_ts=83.3
Total time: 14.10 min
Working directory was: /builds/jb753/turbigen/runs/0000

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