CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > SU2

Turbomachinery: Negative number of recomputed blade row

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 9, 2022, 07:22
Default Turbomachinery: Negative number of recomputed blade row
  #1
New Member
 
M
Join Date: Nov 2022
Posts: 4
Rep Power: 4
Vafi is on a distinguished road
Hi there,

I'm trying to run a turbomachinery case where I modified the APU testcase. The goal is to run a multizone compressor sim, but every time I try to run the case the recomputed blade row becomes negative.


Code:
---------------------- Turbomachinery Preprocessing ---------------------

Initialize Turbo Vertex Structure.
Number of span-wise sections in Zone 0: 44.
TURBOMACHINERY folder creation failed.
Max number of span-wise sections among all zones: 44.
Initialize solver containers for average and performance quantities.
Compute inflow and outflow average geometric quantities.
Transfer average geometric quantities to zone 0.
Inlet area for Row 1: 9.03405e+06 cm^2.
Oulet area for Row 1: 7.07688e+06 cm^2.
Recomputed number of blades for Row 1: -8.96066.
Initialize turbomachinery solution quantities.
Initialize inflow and outflow average solution quantities.
Inlet flow angle for Row 1: 0°.
Outlet flow angle for Row 1: -nan°.

------------------------------ Begin Solver -----------------------------
I imported the mesh using CGNS converting it to .su2 using SU2_DEF. When looking at the mesh it does not look like there is anything wrong. If I switch the turbomachinery marker, e.g :

Code:
MARKER_TURBOMACHINERY= (OUTFLOWPassage, INFLOWPassage)
The blade number becomes positive, but this is rather counterintuitive and the sim still diverges. Is anybody able to help me with this? These are my markers and turbo settings. I converted the testcase to a single zone case for clarity, so it just involves the impeller now.

Code:
TURBOMACHINERY_KIND= AXIAL_CENTRIFUGAL

MARKER_HEATFLUX= (HUB, 0.0, SHROUD, 0.0, BLADE, 0.0)
MARKER_TURBOMACHINERY= (INFLOWPassage, OUTFLOWPassage)
MARKER_INTERNAL= (SHROUDTIPGGISIDE1, SHROUDTIPGGISIDE2, BLDLOW, BLDGEOLOW, BLDHIGH, BLDGEOHIGH)
MARKER_GILES= (INFLOWPassage, TOTAL_CONDITIONS_PT, 101325.0, 288.15, 1.0, 0.0, 0.0, 1.0, 0.0, OUTFLOWPassage, STATIC_PRESSURE_1D, 151213.0, 0.0, 0.0, 0.0, 0.0 , 1.0, 0.0)
MARKER_PERIODIC= (PER1, PER2, 0.0, 0.0, 0.0, 0.0, 0.0, 24.0, 0.0, 0.0, 0.0)
Vafi is offline   Reply With Quote

Old   December 2, 2022, 05:47
Default
  #2
New Member
 
M
Join Date: Nov 2022
Posts: 4
Rep Power: 4
Vafi is on a distinguished road
So it turns out SU2 can be mesh orientation specific, meaning the direction of the outlet vector can have an effect on the code. I managed to solve my problem by rotation the mesh. Previously my outlet vector was pointing in the positive X,Y direction. By rotating the mesh -90deg (around Z axis) the outlet vector pointed in the +X,-Y direction, which fixed my problem. The rotation axis of my mesh is the Z-axis, with the flow entering the impeller channel following the +Z direction.
Vafi is offline   Reply With Quote

Old   January 19, 2025, 05:56
Default
  #3
New Member
 
Join Date: Jan 2022
Posts: 14
Rep Power: 5
akashshankhdhar7 is on a distinguished road
Hi
I have the same issue, but I checked my orientation and it seems to be correct i.e. z-axis is the rotational axis and flow is along the z-axis.

Quote:
---------------------- Turbomachinery Preprocessing ---------------------

Initialize Turbo Vertex Structure.
Number of span-wise sections in Zone 0: 131.
Number of span-wise sections in Zone 1: 61.
Number of span-wise sections in Zone 2: 100.
Number of span-wise sections in Zone 3: 81.
Number of span-wise sections in Zone 4: 101.
Number of span-wise sections in Zone 5: 61.
Max number of span-wise sections among all zones: 131.
Initialize solver containers for average quantities.
Compute inflow and outflow average geometric quantities.
Set span-wise sections between zones on Mixing-Plane interface.
Inlet area for Row 1: 149.303 cm^2.
Oulet area for Row 1: 132.372 cm^2.
Recomputed number of blades for Row 1: -426.15.
Inlet area for Row 2: 109.68 cm^2.
Oulet area for Row 2: 97.936 cm^2.
Recomputed number of blades for Row 2: 82.7513.
Inlet area for Row 3: 83.6041 cm^2.
Oulet area for Row 3: 74.9195 cm^2.
Recomputed number of blades for Row 3: 83.1381.
Inlet area for Row 4: 68.26 cm^2.
Oulet area for Row 4: 62.8176 cm^2.
Recomputed number of blades for Row 4: 94.1531.
Inlet area for Row 5: 57.6897 cm^2.
Oulet area for Row 5: 52.9969 cm^2.
Recomputed number of blades for Row 5: 102.789.
Inlet area for Row 6: 49.9393 cm^2.
Oulet area for Row 6: 45.9317 cm^2.
Recomputed number of blades for Row 6: 115.884.
akashshankhdhar7 is offline   Reply With Quote

Old   January 20, 2025, 06:31
Default
  #4
Member
 
Josh Kelly
Join Date: Dec 2018
Posts: 57
Rep Power: 8
joshkellyjak is on a distinguished road
Can you attach the full preprocessing output and cfg file? Are your periodics matching correctly? Do you get any warning messages? The flow in turbomachinery simulations must follow the positive z-direction (i.e. inflow at min z, outflow at max)
joshkellyjak is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Foam::error::PrintStack almir OpenFOAM Running, Solving & CFD 92 May 21, 2024 07:56
Foam-Extend 4.0 simpleFoam motorbike parallel error? EternalSeekerX OpenFOAM Running, Solving & CFD 0 May 10, 2021 04:55
Cluster ID's not contiguous in compute-nodes domain. ??? Shogan FLUENT 1 May 28, 2014 15:03
DecomposePar unequal number of shared faces maka OpenFOAM Pre-Processing 6 August 12, 2010 09:01
[blockMesh] BlockMesh FOAM warning gaottino OpenFOAM Meshing & Mesh Conversion 7 July 19, 2010 14:11


All times are GMT -4. The time now is 01:45.