Fluid Domain creation for a Axial fan

[Ruhanii 0]

Hi,

I want to design an axial fan using Turbo Machine Workflow and create a fluid domain to perform CFD analysis using ANSYS Fluent. I followed the Axial Fan Tutorial available in the documentation. In this tutorial, a section of the axial fan is created along with the boundary surface. However, I do not see the fluid domain creation process. There is a tutorial video available at this https://youtu.be/9Eo44u43OFI. At 2:27 minutes, the fluid domain is shown, but the creation process is not discussed.

Additionally, I tried following the tutorial in the Documentation under Tutorials/Blade Design/Centrifugal Impeller Modeling, but this option is not available for axial fan design.

After designing the fan, I want to link it to CAESES Geo Engine for ANSYS Workbench and then create a workflow with Fluent. Using the parameters defined in CAESES, I aim to optimize the axial fan to achieve the required output parameters.

Could you please help me create a periodic fluid domain for the axial fan?

Thank you,

Ruhanii Avula

 

[Carl Benz 5]

Hi Ruhanii,

You are right, it is not discussed and not included in the samples. The raw creation of a flow domain for fan like geometries in caeses is usally based on these general steps:

• creation of a boundary surface between two blades
• rotate this surface accordingly to the number of blades to get a periodic sector (at the sample axial fan, a sector of the fan is created somehow similar)
• create the faces at shroud and hub radius (e.g. using surface of revolution, or cutting images from existing hub and shroud surfaces (take care of the edges!))
• create a Brep and close planar faces to build a solid (extend and trim surfaces, if needed)
• build a solid from the blade to
• cut out the blade from the flow domain (both flow domain and fan need to be a solid (closed Brep))
• color the faces during brep operations to give them labels

A more complex and advanced example for an impeller pump is provided here. There, the flow domain is build via feature definition. 

Hope that gives you some inspiration.

Best

Carl

 

[C.Fan 0]

Hi Carl,

Thank you for your kind reply. In fact, I have also encountered the same problem recently: how to create the fluid domain of an axial fan. I plan to establish three regions: (1) inlet domain, (2) rotation domain, and (3) outlet domain. Then export the three domains with STL files separately and use TCFD for calculation.
Although your steps have been described in detail, it is still challenging for beginners. I also reviewed the "Impeller Pump" case you mentioned. Then I attempted to export the feature and re-use it to create a fluid domain, but the results were not satisfactory.
So，could you provide a simple CAESES file or feature for us to learn from?
Thank you very much!

Regards,

Fan

 

[Carl Benz 5]

Hi Fan,

I hope you could find a way to build a periodic flow domain. The segments of the geometry are part in all our samples about fans, propellers and other rotating blades. As the boundary surface creation is dependend on the use case and as some meshing software finds its own periodic surface, we do not worked out THE "best practice" method for creating such a surface.

I attached the axial-fan-sample with an extended boundary surface, which is hopefully what you were looking for.

Best,

Carl

axialfan_extBoundarySurface.cdb

[Praveen 0]

Hello, Carl!
I've been trying to find some resources for this exact situation.
There is a feature definition that already exists for creating flow domain sector (single blade segment) for centrifugal impellers, but not anything equivalent for axial fans or marine propellers.
We'd like to know further steps in this process, such as extending faces to have inlet and outlet segments, and splitting them before and after the fan geometry (to use MRF interfaces in CFD solvers)