[clapaludio]

Hello everyone!


I have a working setup in Workbench for a single passage simulation of a compressor using DesignModeler/BladeEditor, that then outputs to TurboGrid for structured meshing and tip clearance definition, then all to CFX.
The working setup uses a single rotor blade from a .bgd file, and a downstream stator (parasolid); then the sketches for hub, shroud, inlet and outlet are in place to create a FlowPath and ExportPoints as is usual to create a single passage.


What I need to do however is to make this a full annulus geometry where 15 out of 16 blades are standard, and one is modified. While I have successfully put all the blades as I want in DesignModeler, I cannot understand from the documentation how to continue. My objective would be to keep everything as close as possible to how it already behaves in order not to have problems extracting and comparing quantities of interest and also so that the previous TurboGrid settings still work without too much effort (as I do not know if I have the time to remesh everything and do another mesh sensitivity study).


Is it even possible to use ExportPoints again by just copying and rotating the hub-shroud-inlet-outlet and corresponding FlowPath for each blade? Or is my only choice to create a fluid zone for the full annulus by subtraction? Can you point me somewhere where I can learn more?


Thanks everyone for the help. Hope I have been precise enough in my explanation


Cheers!

[zacko]

Interesting question.

I'm just thinking about a way in theory.
Maybe, you create 2 TG setups. One with the original blade and one for the modified. Then, load both into CFX Pre. The original blade will be copied 15 times around the rotation axis - > Here, im not 100% sure. But, hopefully, the result is a nearly full annulus mesh setup with one passage missing. Then, rotate the modified blade passage until it fits into the missing passage to achieve a full annulus. Finally, set the correct interfaces.

But, as I wrote this, I thought about a major problem:
As you modify your blade (idk how much), the created blade passage of the modified file in Turbogrid may deviate from the original one. This may result in problems with my mentioned method in CFX Pre. For example if your wrap angle is bigger or smaller, the created passage will change accordingly. This may be problematic. What do you think?

[clapaludio]

I have tried but unfortunately it does not work. That said, I may have a new solution. I will write it here as a reply if it works, for future reference.

[zacko]

Good luck with that

[clapaludio]

Originally Posted by clapaludio

I have tried but unfortunately it does not work. That said, I may have a new solution. I will write it here as a reply if it works, for future reference.

In the end the new method worked. It may not be the best but in turn it makes it possible to basically keep the meshes as before, however it is a rather manual process.


Basically you put the 15 blades in, and slot in the modified one but tell TurboGrid that this blade is part of a rotor with like 30% more blades so there is a gap between the domains. You run an iteration of this to extract the periodic surfaces and use them to build the domains bridging the different blade to the rest of the rotor.


Then it's just a matter of setting up the full annulus simulation correctly.