Turbomachinery Blade Design

[AkkuAnKa]

Hi,
I am just starting with FreeCAD but I have some experience in Turbomachinery Design. For that purpuse I created my own blade design tool some 3 years ago and I am wondering if there would be any interest for use as an add in to FreeCAD. The Tool has basically the same work flow as ANSYS BladeGen. Output for CFD, FEM and Milling is presently simple STL files. I am happy to share my code, my knowledge and some of my time. I got the idea of sharing it when I so the plugin for ship design.
best regards,
Andre

[Jee-Bee]

I know that in FEM they are busy with an CFD module...
Within that/this purpose it think it would be interesting to have this kind of features.

One thing i think could be interesting is that that kind of features can be created parametrically within FC model.

[AkkuAnKa]

Thanks for the interest. I think large parts could be implemented as macros of existing functionalities. When it comes to the blade design, my code is largely based on the algorithms of Casey, A Computational Geometry for Blades and Internal Flow Channels of Centrifugal Compressors 1982, and Miller, BladeCAD An Interactive Geometric Design Tool for turbomachinery blades, 1996 (NASA Report). What would be more helpfull to get started: Chunks of code or a flow chart ? Whom should I contact ?
best regards,
Andre

[Jee-Bee]

I don't know who knows best about this kind of information.
I put a link in the FEM Board. so i expect that a reaction shall follow...

[andrew.j.smart1988]

Hi,
I am just starting with FreeCAD but I have some experience in Turbomachinery Design. For that purpuse I created my own blade design tool some 3 years ago and I am wondering if there would be any interest for use as an add in to FreeCAD. The Tool has basically the same work flow as ANSYS BladeGen. Output for CFD, FEM and Milling is presently simple STL files. I am happy to share my code, my knowledge and some of my time. I got the idea of sharing it when I so the plugin for ship design.
best regards,
Andre

Yes I am very interested in the code/approach. I'm unfamiliar with FreeCAD plugin design though, and I presume your intent is to speak to someone with such? I presume people would prefer the output to be either NURBs or Bezier curves.

See this MSc Thesis on 'Turbomachinery Blade Design' by R.C.W. de Koning, which uses NURBs (pdf link at bottom of page).

I have been unable to find it, so I don't think that author had released their FreeCAD python "plugin" as open source. Then again, maybe the author had done so in German, I can't find it! It appears the author is here on the forum, you can try chatting with him about his approach/workflow, or just browse through his posts.

Here's a work in progress 'Turbomachinery Blade Design' Bachelor of Aerospace Engineering project by Ionuț Alexandruu, Coşuleanu who uses Bezier curves in Matlab (not a plugin to FreeCAD though).

There may be other related works, I'm still searching.

[LZ2017]

Hi Andre, you may have all the answers I badly need; I am working on a radial inflow turbine and the meridional design is OK. I need an algorithm to build the 3D model. It seems you have done the development.
How can I use your application ?
Thanks, Liviu

[andrew.j.smart1988]

Hi Andre, you may have all the answers I badly need; I am working on a radial inflow turbine and the meridional design is OK. I need an algorithm to build the 3D model. It seems you have done the development.
How can I use your application ?
Thanks, Liviu

Hi Liviu from Canada,
I've discovered a couple more open source projects since my last post. T-AXI and T-Blade3 (formerly 3DBGB).
http://gtsl.ase.uc.edu/T-AXI/
http://gtsl.ase.uc.edu/T-AXI/BD%20Suite ... index.html
http://gtsl.ase.uc.edu/t-blade3/

The authors of T-AXI include:
Professor Mark G. Turner, University of Cincinnati
Ali Merchant, Massachusets Institute of Technology
Dario Bruna, University of Genoa, Italy

Read the masters thesis on the T-Blade3 page. The literature review is very good. Make sure you've read Miller, BladeCAD An Interactive Geometric Design Tool for turbomachinery blades, 1996 (NASA Report) as well- it is important to understand why different coordinate systems are used in turbomachinery blade design.

I am working on a 1 stage radial compressor. For my workflow it appears I must use T-AXI as the first step to generate part of the input for T-Blade3 as Kiran Siddappaji writes in their masters thesis §2.1:

The input file also contains the xs and rs coordinates for all the nspn streamlines defined from an axisymmetric run like T-Axi [16, 17, 18, 19], or by smooth construction curves between the hub and the casing.

In LinuxTAXI/Documentation/T-AXI-API-ReadMe_New.txt it says:

To create input file for the 3D geometry generator, 3DBGB from T-Axi

Graphics version:

>taxi_D -ga casename
This creates 3dbgbinput files for all bladerows.

OR


Non-graphics version:

>taxi_driver -ga casename

Read the example turbine input files ("t" in the .tti/.tts file extensions means turbine, "c" in the .tci/.tcs file extensions means compressor).

I'm still figuring out how to use the software from start to finish. I'll make a write up on my workflow once I've figured things out.

I hope this helps you in your work you badly need

[hammax]

...thanks for the literature cites. Especially t-blade3.
I am/was also a "little bit" interested in turbomachinery e.g. an APU-idea for hybrid electrovehicles....
https://forum.freecadweb.org/viewtopic. ... 60#p170444

[LZ2017]

Hi andrew.j.smart1988, thank you for the input. I am desperate enough to find a solution, last week I came across the website you are mentioning, downloaded the files but, in spite of my enthusiasm, I have to concede, could not make any sense without a tutorial.
I do hope you will get to the bottom of the matter and then, share the findings. I am sure you picked up the right user name...
So, it's either you or Andre (I searched several books but wasn't able to draw any useful chain of equations...)
For the time being, I will follow your suggestions, thanks !

[andrew.j.smart1988]

Here's another great piece of literature using T-AXI (MSc Thesis): Soumitr Dey - Wind Turbine Blade Design System – Aerodynamic and
Structural Analysis.

I made a FreeCAD script automating the Kaplain method to make streamlines from the LE/TE blade angles and the streamline in the meridional plane. I'll post it once I get it more polished. It would be useful for approximating the blade length and chord length for input into T-AXI (via the Solidity & Aspect Ratio inputs). I suppose you could manually process the streamlines into a blade within FreeCAD, but the T-AXI/3DBGB route should be much better.