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: 4e5

# 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
      q_thick: [0.05, 0.12, 0.3, 0.2, 0.0, 0.1]
      q_camber: [0., 4., 0.0]
    - spf: 0.5
      q_thick: [0.05, 0.12, 0.3, 0.2, 0.0, 0.1]
      q_camber: [0., 5., 0.0]
      tip: 0.01

# 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: 100
  n_step_ramp: 1000

# 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:
  # Copy spanwise profiles at outlet to the inlet
  # to model a repeating stage
  repeat:

# 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: [2.05, 4.05]
    variable: Ys
  # Mid-span Mach
  - type: contour
    coord: spf
    value: 0.5
    variable: Ma_rel

# operating_point:
#   # Omega_adjust: 0.2
#   # PR_ts_adjust: -0.2
#   # mdot_adjust: 0.1
#   pid: [0.5, 0.1, 0.0]
#

Log output

*** TURBIGEN v2.3.0 ***
Starting at 2025-05-09T16:31:53
Working directory: /builds/jb753/turbigen/runs/0000
Iterating for max 20 iterations...
Convergence status:
  deviation: False
  incidence: False
  mean_line: False
  repeat: False
  Min Dev[0] DDev[0] Dev[1] DDev[1] Inc[0] DInc[0] Inc[1] DInc[1] Ys[0] DYs[0] Ys[1] DYs[1] Repeat_dTo
------------------------------------------------------------------------------------------------------
  1.8   4.07      -2   6.36      -2   -122      -2    132       2 0.039  0.009 0.078  0.014      0.017
 2.05   1.88   -1.88   4.17      -2  -18.9   -0.94   30.7    1.53 0.035  0.003 0.077  0.006      0.004
 2.01   -0.1     0.1   2.05      -2   7.55   0.378   -5.9   -0.29 0.029  -0.00 0.071  0.000      0.007
    2  -0.09   0.095  -0.15   0.153    6.3   0.315  -15.6   -0.77 0.027  -0.00 0.070  -0.00      0.006
    2  0.028   -0.02  -0.10   0.103  -5.41   -0.27  -2.71   -0.13 0.029  -0.00 0.071  0.000      0.002
Convergence status:
  deviation: True
  incidence: True
  mean_line: True
  repeat: False
  Min Dev[0] DDev[0] Dev[1] DDev[1] Inc[0] DInc[0] Inc[1] DInc[1] Ys[0] DYs[0] Ys[1] DYs[1] Repeat_dTo
------------------------------------------------------------------------------------------------------
    2  -0.03   0.031  0.005   -0.00  -3.25   -0.16  -1.87   -0.09 0.029  0.000 0.071  0.000      0.001
    2  -0.01   0.012  -0.00   0.009  -2.23   -0.11  -1.19   -0.05 0.029  0.000 0.071  0.000      0.000
Finished iterating, converged=True.
   Variable  Nominal  Actual   Err_abs  Err_rel/%
-------------------------------------------------
        Ma2      0.7   0.696   0.00447      0.639
      Ys[0]   0.0296  0.0298  -0.00021      -0.72
      Ys[1]   0.0715  0.0717  -0.00022      -0.31
fac_Ma3_rel        1       1  -0.00454     -0.454
       mdot      500     500     0.345     0.0689
       phi2      0.6   0.598   0.00152      0.254
        psi      1.6    1.59   0.00735       0.46
       rrms        1       1         0          0
    zeta[0]        1       1  -0.00039     -0.039
    zeta[1]        1       1   -0.0035      -0.35
      PR_ts             1.82
      PR_tt              1.7
    Ma3_rel            0.701
     Alpha1            -24.4
        Lam            0.522
       htr2            0.875
     eta_tt            0.915
     eta_ts            0.814
      Omega              353
Efficiency/%: eta_tt=91.5, eta_ts=81.4

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