[CFDci]

Hi everyone,

I am fresh in FineTurbo. There is a option on interface called "import and link CAD " I can import my centrifugal comressor in IGS format(exported using solidworks) but I couldn't aerodynamic definition(link to hub, link to trailing edge, periodicity etc.) of my compressor. I got many errors such as there is no geometry groups although I see before. Is there anyone who done such an analysis.

I added screens about what I mean.

http://imgur.com/a/TQjxb

Thanks indeed

[DarylMusashi]

Hello CFDci,
thank you for using NUMECA software . Why exactly is it not possible to link for example the desired edges to leading/trailing edge? Can you only select your geometry as a whole? Maybe it is necessary do process your exported geometry file with IGG (just a first idea).

[Hamidzoka]

Hi
According to my experiences, the best method of importing a blade geometry to Autogrid is to make 2d sections out of the 3d airfoil and then import section points throgh a geomturbo format. But before doing this the blade should be put on its right positon. If you are interested i can provide you with more detailed informaton.

Regards

[CFDci]

Hi Hamidzoka,

thank you indeed, after working on Numeca's tutorials, finally I deduced like you. All tutorials were done using .dat file including row coordinates or geomturbo file as you know. If you have provide details somehow, I'll be glad to hear you.

Best Regards

[Hamidzoka]

Hi
in order to make a geomturbo file following steps come to my mind:
*Extracing HUB and SHROUD curves:
- put the 3D blade in its realistic position relative to its rotation axis. make sure that rotation axis is z. if not, u need to change it.
- extract hub and shroud wall curves to define the gas path. these curves are axisymmetric having just r and z components.
- extract defining points of hub and shroud curves in a ZR coordinate system and put them in the right place in your geomturbo file. (if you have them in XYZ you had better to convert them in RZ)

*EXtracting AIRFOIL sections:
- define some section planes from hub to shroud of the blade and exploit 2D airfoil sections out of it. the more the sections the more exact the geometry.
- try to divide each 2D airfoil curve into "pressure side" and "suction side" separated curves.
- exploit the curve defining points. if the number of points are not adequate define additional supporting points on curves specially on those regions having large curvature i.e. leading edge and trailing edge. "adding points on a curve" is a standard capability that most of CAD softwares have.
- for each curve (no matter SS or PS), extract XYZ coordinates of each single point and sort them from LE to TE. this can be manually done. but if your CAD sofware accepts programming, you can write a simple code to make this process quick and automatic.
- repeat this procedure from hub to shroud sections
- then put the points and sections into the geomturbo format. you can easily find a sample geomturbo in NUMECA tutorials. note that in a gemturbo file sections numbering strats form hub (as 1) to the shroud.
- please note that geomturbo has two styles: the one develpoed for Autogrid4 which has a simple structure and easy to implement and the one developed for Autogrid5 which is quite sophisticated! use the simpler format and don't worry since it can be used in Autogrid5 module as well.

regards

[CFDci]

Dear Hamidzoka,

thank you for reply. You gave very important explanation to me, I hope I'll do my analysis of radial compressor with the help your words. For the beginners like me, it will be harder a it instead of using prepared CAD but worth to try always.

Best Regards

[Pierre-Alain]

Hi CFDci,

Actually the workflow using the Import CAD feature is more straightforward in your case. According to the geometry shown on your link, it seems you have all entities required to link the different elements to the AutoGrid5 project. Only a shroud curve does not seem to be displayed.

Your configuration includes a main blade and a splitter blade per impeller passage. Your impeller row definition in the row list of AutoGrid5 should therefore include both. Before linking the blades, you should Add a Blade by right-clicking on the impeller name in the list and by selecting the option.

Then in the Import CAD window, after importing the IGES file, you can first link the hub curve and then the shroud curve to the AutoGrid5 project after selecting them in the Import CAD window.

For the main blade definition, you only need to select one main blade surface in the Import CAD (assuming they are all identical) and link it to the AutoGrid5 project using Link to Blade (if you have a double blunt at LE/TE, please link pressure and suction sides separately with the appropriate link as shown on your screenshot). Please note that the corresponding blade entity simply needs to be selected under the impeller row definition in the row list of AutoGrid5 before linking. So that AutoGrid5 knows to which blade the surface(s) should be associated.

The same process can be applied for the splitter blade definition.

I hope this information will be useful.

Best regards,

Pierre-Alain Hoffer
NUMECA International.

[CFDci]

Dear Pierre-Alain

Thank you very much. I think your and Hamidzoka's explanations made me clear. Now, it is time to work on it!

Best Regards