Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Combustor element changes area between DESIGN and OFF-DESIGN points #74

Open
flight-test-engineering opened this issue Nov 9, 2024 · 0 comments
Open

Combustor element changes area between DESIGN and OFF-DESIGN points #74

flight-test-engineering opened this issue Nov 9, 2024 · 0 comments

Comments

@flight-test-engineering
Copy link

I first checked if there were any open issues regarding matching design and off-design combustor areas and was going to push a PR myself, when I saw PR#62.

I am documenting here the issue to support that PR.

Descripion

When the exemple given in "pyCycle/example_cycles/high_bypass_turbofan.py" is run, I get the following result, showing a calculated area for DESIGN.burner.Fl_O.stat:area=169.041. Further down in the results, for the Off-Design results, I get OD_part_pwr.burner.Fl_O.sta:area=1550.003 (see excerpt from hbtf_view results file):


----------------------------------------------------------------------------
                              POINT: DESIGN
----------------------------------------------------------------------------
                       PERFORMANCE CHARACTERISTICS
    Mach      Alt       W      Fn      Fg    Fram     OPR     TSFC      BPR 
 0.80000  35000.0 344.303  5900.0 14232.2  8332.2  30.094  0.63072    5.105
------------------------------------------------------------------------------------------------------------------------------------------------
                            FLOW STATIONS
------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------
Flow Station           |          tot:P        tot:T        tot:h        tot:S       stat:P       stat:W      stat:MN       stat:V    stat:area
------------------------------------------------------------------------------------------------------------------------------------------------
DESIGN.fc.Fl_O         |          5.273      444.404      -23.983        1.665        3.458      344.303        0.800      778.619     2687.027
DESIGN.inlet.Fl_O      |          5.267      444.404      -23.983        1.665        3.623      344.303        0.751      735.912     2750.930
DESIGN.fan.Fl_O        |          8.876      524.338       -4.822        1.668        7.687      344.303        0.458      503.511     2388.267
DESIGN.splitter.Fl_O1  |          8.876      524.338       -4.822        1.668        8.302       56.397        0.310      345.152      540.175
DESIGN.splitter.Fl_O2  |          8.876      524.338       -4.822        1.668        7.715      287.906        0.452      497.172     2017.239
DESIGN.duct4.Fl_O      |          8.833      524.338       -4.822        1.669        8.256       56.397        0.312      347.007      540.160
DESIGN.lpc.Fl_O        |         17.092      641.883       23.430        1.672       16.019       56.397        0.306      376.175      314.644
DESIGN.duct6.Fl_O      |         16.919      641.883       23.430        1.673       15.499       56.397        0.356      436.748      278.279
DESIGN.hpc.Fl_O        |        158.515     1276.476      180.824        1.689      152.230       49.884        0.244      419.921       52.574
DESIGN.bld3.Fl_O       |        158.515     1276.476      180.824        1.689      149.148       41.480        0.300      514.548       36.216
DESIGN.burner.Fl_O     |        149.955     2857.000      176.427        1.947      148.948       42.514        0.102      256.960      **169.041**
DESIGN.hpt.Fl_O        |         41.484     2052.072        9.419        1.932       38.045       50.918        0.365      776.801      184.766

.
.
.
----------------------------------------------------------------------------
                              POINT: OD_part_pwr
----------------------------------------------------------------------------
                       PERFORMANCE CHARACTERISTICS
    Mach      Alt       W      Fn      Fg    Fram     OPR     TSFC      BPR 
 0.80000  35000.0 344.303  5900.0 14232.2  8332.2  30.094  0.63072    5.105
------------------------------------------------------------------------------------------------------------------------------------------------
                            FLOW STATIONS
------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------
Flow Station           |          tot:P        tot:T        tot:h        tot:S       stat:P       stat:W      stat:MN       stat:V    stat:area
------------------------------------------------------------------------------------------------------------------------------------------------
OD_part_pwr.fc.Fl_O    |          5.273      444.404      -23.983        1.665        3.458      344.303        0.800      778.619     2687.027
OD_part_pwr.inlet.Fl_O |          5.267      444.404      -23.983        1.665        3.623      344.303        0.751      735.912     2750.930
OD_part_pwr.fan.Fl_O   |          8.876      524.338       -4.822        1.668        7.687      344.303        0.458      503.511     2388.267
OD_part_pwr.splitter.Fl|          8.876      524.338       -4.822        1.668        8.302       56.397        0.310      345.152      540.175
OD_part_pwr.splitter.Fl|          8.876      524.338       -4.822        1.668        7.715      287.906        0.452      497.172     2017.239
OD_part_pwr.duct4.Fl_O |          8.833      524.338       -4.822        1.669        8.256       56.397        0.312      347.007      540.160
OD_part_pwr.lpc.Fl_O   |         17.092      641.883       23.430        1.672       16.019       56.397        0.306      376.175      314.644
OD_part_pwr.duct6.Fl_O |         16.919      641.883       23.430        1.673       15.499       56.397        0.356      436.748      278.279
OD_part_pwr.hpc.Fl_O   |        158.515     1276.476      180.824        1.689      152.230       49.884        0.244      419.921       52.574
OD_part_pwr.bld3.Fl_O  |        158.515     1276.476      180.824        1.689      149.148       41.480        0.300      514.548       36.216
OD_part_pwr.burner.Fl_O|        149.955     2857.000      176.427        1.947      149.943       42.514        0.011       27.879     **1550.003**
OD_part_pwr.hpt.Fl_O   |         41.484     2052.072        9.419        1.932       38.045       50.918        0.365      776.801      184.766

Further investigation showed that in class HBTF(pyc.Cycle), the Combustor element is added on line 54 of "high_bypass_turbofan.py":
self.add_subsystem('burner', pyc.Combustor(fuel_type=FUEL_TYPE))

Then, on line 370 of "high_bypass_turbofan.py", class MPhbtf() creates an instance of HBTF (line 298) and on line 370, the pyc_use_default_des_of_conns() method is invoked.
Looking in "mp_cycle.py", where class MPCycle is defined, the method expects a list of default connections for a given element to be in "default_des_od_conns"

Proposed fix:

Add the following to Combustor class' "initialize" method:

    self.default_des_od_conns = [
        # (design src, off-design target)
        ('Fl_O:stat:area', 'area')
    ]

Results:

After implementing this fix, I get the following results from running the same example given in "pyCycle/example_cycles/high_bypass_turbofan.py":

----------------------------------------------------------------------------
                              POINT: DESIGN
----------------------------------------------------------------------------
                       PERFORMANCE CHARACTERISTICS
    Mach      Alt       W      Fn      Fg    Fram     OPR     TSFC      BPR 
 0.80000  35000.0 344.303  5900.0 14232.2  8332.2  30.094  0.63072    5.105
------------------------------------------------------------------------------------------------------------------------------------------------
                            FLOW STATIONS
------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------
Flow Station           |          tot:P        tot:T        tot:h        tot:S       stat:P       stat:W      stat:MN       stat:V    stat:area
------------------------------------------------------------------------------------------------------------------------------------------------
DESIGN.fc.Fl_O         |          5.273      444.404      -23.983        1.665        3.458      344.303        0.800      778.619     2687.027
DESIGN.inlet.Fl_O      |          5.267      444.404      -23.983        1.665        3.623      344.303        0.751      735.912     2750.930
DESIGN.fan.Fl_O        |          8.876      524.338       -4.822        1.668        7.687      344.303        0.458      503.511     2388.267
DESIGN.splitter.Fl_O1  |          8.876      524.338       -4.822        1.668        8.302       56.397        0.310      345.152      540.175
DESIGN.splitter.Fl_O2  |          8.876      524.338       -4.822        1.668        7.715      287.906        0.452      497.172     2017.239
DESIGN.duct4.Fl_O      |          8.833      524.338       -4.822        1.669        8.256       56.397        0.312      347.007      540.160
DESIGN.lpc.Fl_O        |         17.092      641.883       23.430        1.672       16.019       56.397        0.306      376.175      314.644
DESIGN.duct6.Fl_O      |         16.919      641.883       23.430        1.673       15.499       56.397        0.356      436.748      278.279
DESIGN.hpc.Fl_O        |        158.515     1276.476      180.824        1.689      152.230       49.884        0.244      419.921       52.574
DESIGN.bld3.Fl_O       |        158.515     1276.476      180.824        1.689      149.148       41.480        0.300      514.548       36.216
DESIGN.burner.Fl_O     |        149.955     2857.000      176.427        1.947      148.948       42.514        0.102      256.960      **169.041**
DESIGN.hpt.Fl_O        |         41.484     2052.072        9.419        1.932       38.045       50.918        0.365      776.801      184.766

.
.
.
----------------------------------------------------------------------------
                              POINT: OD_part_pwr
----------------------------------------------------------------------------
                       PERFORMANCE CHARACTERISTICS
    Mach      Alt       W      Fn      Fg    Fram     OPR     TSFC      BPR 
 0.80000  35000.0 344.303  5900.0 14232.2  8332.2  30.094  0.63072    5.105
------------------------------------------------------------------------------------------------------------------------------------------------
                            FLOW STATIONS
------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------
Flow Station           |          tot:P        tot:T        tot:h        tot:S       stat:P       stat:W      stat:MN       stat:V    stat:area
------------------------------------------------------------------------------------------------------------------------------------------------
OD_part_pwr.fc.Fl_O    |          5.273      444.404      -23.983        1.665        3.458      344.303        0.800      778.619     2687.027
OD_part_pwr.inlet.Fl_O |          5.267      444.404      -23.983        1.665        3.623      344.303        0.751      735.912     2750.930
OD_part_pwr.fan.Fl_O   |          8.876      524.338       -4.822        1.668        7.687      344.303        0.458      503.511     2388.267
OD_part_pwr.splitter.Fl|          8.876      524.338       -4.822        1.668        8.302       56.397        0.310      345.152      540.175
OD_part_pwr.splitter.Fl|          8.876      524.338       -4.822        1.668        7.715      287.906        0.452      497.172     2017.239
OD_part_pwr.duct4.Fl_O |          8.833      524.338       -4.822        1.669        8.256       56.397        0.312      347.007      540.160
OD_part_pwr.lpc.Fl_O   |         17.092      641.883       23.430        1.672       16.019       56.397        0.306      376.175      314.644
OD_part_pwr.duct6.Fl_O |         16.919      641.883       23.430        1.673       15.499       56.397        0.356      436.748      278.279
OD_part_pwr.hpc.Fl_O   |        158.515     1276.476      180.824        1.689      152.230       49.884        0.244      419.921       52.574
OD_part_pwr.bld3.Fl_O  |        158.515     1276.476      180.824        1.689      149.148       41.480        0.300      514.548       36.216
OD_part_pwr.burner.Fl_O|        149.955     2857.000      176.427        1.947      148.948       42.514        0.102      256.960      **169.041**
OD_part_pwr.hpt.Fl_O   |         41.484     2052.072        9.419        1.932       38.045       50.918        0.365      776.801      184.766

Recommendation

Merge PR#62
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
1 participant
@flight-test-engineering