Transient blade row model data instancing for odd number of blades

Flowiseverything · September 10, 2021, 02:20

Hello everyone,

I searched it in the forum but I did not get anything about this problem.
I hope to explain it in a clear way.

I am doing a centrifugal fan analysis in CFX using transient blade row model.
I am using the fourier transform method. The number of blade of the fan is an odd number (11 let's say). In fourier transformation method, I have to model two blade to sample between the blade passages. So I modeled one blade passage first. Then I increased the number of passages to two using turbo rotation in turbo mode. So I have two blade passages in my simulation. The calculations have been made and everything is fine with my analysis. But the problem is starting at this point. I want to show te result for 17 blades. So I have to use data instancing. But I have 2 blade in my simulation and I have to show the results for 11 blades. The blade number in the analysis is even but the real number of blades is odd. How can I show the results for 11 baldes? Maybe there is a way to do it but I could not find it. I am adding some pictures to explain my problem.

Thank you for your help already.

[IMG]https://im.ge/i/QJJCb4
https://im.ge/i/QJJEGC[/IMG]

Opaque · September 10, 2021, 08:22

As far as I know, there is no way, so you can either show the 10 blade model and miss one passage, or instance 6 copies (12 blades), and if the solution is well converged the overlap copy should match the first passage.

Have you tried creating the locator on the mesh regions for a single passage instead of using the "physics regions" of the model? That is you can instance the model, and see if the mesh regions are also instanced and check what you can get out of this approach.

Flowiseverything · September 10, 2021, 09:32

Dear opaque,

Thank you for your advice.
Actually I tried to inctance as 12 blades. Despite the analysis were converged, pressure contour did not fit.
I didn't try to create control points in mesh.
I have to use pics. and animations for my result report. Visiual report must seem good.

But I will try what you said.

Thanks again for your advice.

September 10, 2021, 02:20	Transient blade row model data instancing for odd number of blades	#1
Flowiseverything New Member Not applicable Join Date: Dec 2015 Posts: 2 Rep Power: 0	Hello everyone, I searched it in the forum but I did not get anything about this problem. I hope to explain it in a clear way. I am doing a centrifugal fan analysis in CFX using transient blade row model. I am using the fourier transform method. The number of blade of the fan is an odd number (11 let's say). In fourier transformation method, I have to model two blade to sample between the blade passages. So I modeled one blade passage first. Then I increased the number of passages to two using turbo rotation in turbo mode. So I have two blade passages in my simulation. The calculations have been made and everything is fine with my analysis. But the problem is starting at this point. I want to show te result for 17 blades. So I have to use data instancing. But I have 2 blade in my simulation and I have to show the results for 11 blades. The blade number in the analysis is even but the real number of blades is odd. How can I show the results for 11 baldes? Maybe there is a way to do it but I could not find it. I am adding some pictures to explain my problem. Thank you for your help already. [IMG]https://im.ge/i/QJJCb4 https://im.ge/i/QJJEGC[/IMG]

September 10, 2021, 08:22		#2
Opaque Senior Member Join Date: Jun 2009 Posts: 1,804 Rep Power: 32	As far as I know, there is no way, so you can either show the 10 blade model and miss one passage, or instance 6 copies (12 blades), and if the solution is well converged the overlap copy should match the first passage. Have you tried creating the locator on the mesh regions for a single passage instead of using the "physics regions" of the model? That is you can instance the model, and see if the mesh regions are also instanced and check what you can get out of this approach. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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September 10, 2021, 09:32		#3
Flowiseverything New Member Not applicable Join Date: Dec 2015 Posts: 2 Rep Power: 0	Dear opaque, Thank you for your advice. Actually I tried to inctance as 12 blades. Despite the analysis were converged, pressure contour did not fit. I didn't try to create control points in mesh. I have to use pics. and animations for my result report. Visiual report must seem good. But I will try what you said. Thanks again for your advice.