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Hai, I'm doing my final year project with the title of optimization to reduce total ship resistance. To evaluate the resistance, I'm using Numeca Fine Marine but I'm having problem to connect to the software. I don't quiet understand what file should be inputted in the input file and result file. Also, about the meshing, do I need to mesh inside CAESES or NUMECA FINE MARINE?

Thank you in advance.

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Dear Solehah,

with HEXPRESS Numeca Fine/Marine offers a powerful meshing tool which is well matched to their requirements for CFD. Afaik the input file for Numeca (output in CAESES) would be a domain either half or symmetric in colored STL. The only pitfall I am aware of is, that HEXPRESS does not like triangular patches. Hence, if you have them, you would need to join them with a neighboring patch so that the cells can "float" across the patch boundaries (see below image where I colored the small triangular patch in turquoise instead of grey to avoid the described singularity).

image.thumb.png.494c07b2a900061ba6d92af12f176578.png

As an Input to CAESES any text file containing the information of interest (resistance?) should do just fine.

Cheers
Heinrich

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Dear Heinrich,

Thank you for the speedy reply.

I'm trying to mesh the hull form using mesh engine, but it only accepts surface while my geometry is brep. Can you give me advice on how to mesh using other method beside mesh engine? I had tried extracting the surface, but it appeared 'damaged'.

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Dear Solehah,

A Mesh Engine will only allow you to generate surfaces meshes as you would need them for potential flow simulations i.e. for wave making resistance. To run ranse CFD in Fine/Marine you would need to use their HEXPRESS grid generator and supply the flow domain as an STL.  

Best regards
Heinrich

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Dear Heinrich,

Is the setting correct? I already got the stl file from Numeca Fine Marine, it contain both the hull and the domain. But I'm not sure if the stl file already meshing or not. When I try running, it shows like the picture I attached. caeses2.thumb.jpg.443264c967b512439386944bb8aa2cac.jpgcaeses.thumb.jpg.4681e6385207ca148e5da3a7ecd0ee06.jpg

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Dear Solehah,

at least I can't see anything that's obviously wrong from the screen shots. If you have an STL I would recommend that you start by setting everything up in Numeca (completely independent from CAESES). Once things are meshing and running/converging the way you want them to, you can go back to testing the CAESES integration. This way it's easier to know where to trouble shoot...

Cheers,
Heinrich

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I have done running in NUMECA. Meshing and so on. Can you give me some advice on how to connect with CAESES. Such as what file should the geometry be imported? What kind of file should be imported; does it need some programming from NUMECA for the input file. For result file, does it need PNG file from CFView?

I had already tried running CAESES after input the files, but the NUMECA interface pop-out. It does not run in the background and did not get the desired output which is resistance. Based on the video on Youtube, shape optimization using Caeses and STAR-SSM+, the star-ccm seems to be running in the background and its interface does not pop-out.

 

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Dear Solehah,

you can refer to the provided tutorials on software connection. The basic principles are always very similar. After you have tested things manually you should know what geometry is needed and in which format. My guess is a colored STL of half the domain with the ship substracted from the domain at roughly the right floating condition. Extra care needs to be take to account for triangular patches as I mentioned in my first post.

If you want CAESES to read in pictures generated from Numeca (or any other tool in your chain), PNG works fine.

You will want to run Numeca in batch mode to avoid the GUI showing up. 

Best regards,
Heinrich

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Dear Heinrich,

I have sent the file using personal massage. Hope you can give some feedback on the setting.

Thank you. 

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Dear Solehah,

since this is a forum, I'd would like to ask if you can provide a (possibly simplified) version of your project that you are willing to share with other users? This way we can create a knowledgebase that allows the entire CAESES community to benefit.

Best regards,
Heinrich

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Dear Solehah,

thanks for preparing the file. Here's a few comments:

1. I can see that you have a number of individual Trimesh Parts. None of them has a color. Typically what you would want is a watertight geometry of the domain with the individual patches colored (the color names will be exported as the names of your boundary conditions). I recommend you color the individual parts and join them together in a single Trimesh like this:

image.thumb.png.c3e87887173c8238c7c3a9c3471cd8d0.png

2. Make sure to reference to the exported geometry in your sim scripts (maybe I just overlookerd it, but I could not find the file names you used for the exports in there. Lines 8-9 in your existingShip.iec file don't look good.

3. Your Connector runs the local Application FineMarine without any additional arguments. I imagine that you either need to specify the sim file as argument or, alternatively come up with a batch file that takes care of running things.

4. If you want to have parameters for certain inputs you will need to assign them to your configuration (i.e. drag & drop):

image.thumb.png.2f3e77ed1c6475d9d6af3c5a81b9ac48.png

I'll leave it at that for now. If you still run into trouble, I highly recommend you follow through a few tutorials on the subject. The procedure is always very similar.

Best regards,
Heinrich

 

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Dear Heinrich,
Sorry for disturb you. I have some question for number 3 which is "3. Your Connector runs the local Application FineMarine without any additional arguments. I imagine that you either need to specify the sim file as argument or, alternatively come up with a batch file that takes care of running things."

For the batch file, do you have any example or explanation what i need to put in the content/script ?

Thank you in advance

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