Axial turbine

Download this example

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]
      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: 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 v2.7.0 ***
Starting at 2025-08-15T15:57:08
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]
-------------------------------------------------------------------------------------------
 2.76  -69.8      -2   67.3       2  0.563   -0.56  0.037   -0.03 0.024  0.002 0.064  0.007
 2.75  -66.1      -2   36.5    1.82  -0.11   0.114  0.133   -0.13 0.025  0.001 0.069  0.006
 2.77  -62.1      -2   30.8    1.54  -0.10   0.109  0.097   -0.09 0.025  0.000 0.069  0.003
 2.78  -31.9   -1.59   25.9     1.3  -0.11   0.114  0.194   -0.19 0.025  0.000 0.068  0.001
 2.79  -26.8   -1.34   21.8    1.09  -0.09   0.093  0.048   -0.04 0.024  -9.26 0.068  0.000
  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]
-------------------------------------------------------------------------------------------
 2.78   11.6    0.58   18.4   0.921  -0.07   0.077  0.076   -0.07 0.024  -7.75 0.068  0.000
Finished iterating, converged=True.
   Variable  Nominal  Actual   Err_abs  Err_rel/%
-------------------------------------------------
        Ma2      0.7   0.694    0.0055        0.8
      Ys[0]   0.0248  0.0247   7.7e-05       0.31
      Ys[1]   0.0683  0.0684  -0.00015      -0.21
fac_Ma3_rel        1       1   -0.0047       -0.5
       mdot      500     500      0.43        0.1
       phi2      0.6   0.599   0.00086        0.1
        psi      1.6    1.59     0.012        0.8
       rrms        1       1         0        0.0
    zeta[0]        1       1   -0.0012      -0.12
    zeta[1]        1       1    -0.004       -0.4
      PR_ts             1.82
      PR_tt             1.69
    Ma3_rel              0.7
     Alpha1            -24.6
        Lam            0.522
       htr2            0.876
     eta_tt            0.919
     eta_ts            0.816
      Omega              353
Efficiency/%: eta_tt=91.9, eta_ts=81.6
Total time: 16.82 min
Working directory was: /builds/jb753/turbigen/runs/0000

Plots