Optimization of an IGES imported geometry

[Ms. Argyris Apostolidis 0]

Hey everyone,

 

I am new to CAESES and i wonder if it is possible to parametrize an IGES imported geometry , and if so how can i do that.

Thanks in advance
Argyris Apostolidis

[Matthias Maasch 21]

Hi Argyris,

 

thanks for your acutally very important question. First of all, to answer your question: YES!

 

But there are a few things to consider first.

 

When speaking of parametric modeling we have to clearify which parametrization fits your needs best. We distinguish between partially-parametric modeling and fully-parametric modeling. Whereas the partially-parametric approach is based on shifting and deforming the import geometry (such as IGES', STLs or Offsets) and is therefore limited in form variation, the fully-parametric approach re-builds the import from scratch and thus provides an independend and very variable geometry model. A third option of modeling is to combine both approaches in one model.

 

As you are new to CAESES I would strongly recommend to go through some tutorials step by step. You can find the tutorials in the Documentation Browser > Tutorials. After going through the basic "Getting Started" tutorials to get a basic idea of the software you can either have a look into the "Meta Surface" tutorials to learn how to model in a fully-parametric way or you can study tutorials such as Hull Variation and Lackenby variation (assuming you want to model a ship hull) to learn about the partially-parametric approach. In the samples section (Documentation Browser > Samples) you can find a lot nice samples for both approaches.

 

Partially-parametric modeling:

 

I would say using the partially-parametric approach is the number one choice for beginners. It is easy to understand and fast to set up. Furthermore it can be very powerful when set up nicely. To get an overview of some possible setups you can have a look into the "Partially Parametric Modeling" samples. Again, if you are concerned with ship hulls you should be able to copy the setups in order to use it for your import. What to do first:

 

1. Import your IGES geometry via File > Import > IGES

2. Create Image Surfaces via CAD > Surfaces > Imagesurface of the geometry parts you want to have parameterized. If the form change should be applied to a lot of surfaces you can also create a surface group and based on that an image surface group.

3. Setup shift functions (This step is the major part of the process and cannot be explained in a few sentences).

 

Note: Shifts can be time-consimung operations. In order to provide a good workflow you can easily visualise the form change via sections. The update times of sections are much shorter compared to several NUBS surfaces.

 

Fully-parametric modeling:

 

This type of modeling takes a bit longer to learn but it is definitly worth it! To make life easier for you, CAESES comes up with some helpful features. You can find these features in Features > Hull Design (again assuming you want to model ship hulls :) ). One particular feature is probably very interesting for your case in the first place: Analyse Offset Data. In order to be able to use this feature:

 

1. Import your IGES

2. Create sections on the hull. Therefore you can put all surfaces in a surface group and use this group as input for the sections (CAD > Offsets > Section Group)

3. Create the feature and use the section group as input. Adjust draft and Lpp. This will give you some basic curves describing the hull, such as FOB, FOS and DWL.

 

These curves can be your starting point of modeling. As you will know from the tutorials (Meta Surface tutorials) you can use these curves for the functional surfaces. All further steps should become clearer after you did the tutorials.

 

I would be happy to give you further support.

 

If you have any more questions, do not hesitate to ask!

 

Best regards

 

Matthias

 

 

 

[Ms. Argyris Apostolidis 0]

Hi Matthias,

 

thank you very much for your detailed answer! I am interested in optimizing parts of a formula sae car ( if you are familiar with the competition) especialy rear and front wing. 
I went through some basic tutorials and now i am going to see your suggestions.
Another question: I've seen that it is possible to couple CAD with CFD through caeses, i wonder what happens with the Mesh? I use beta's ANSA for the generation of the mesh is it possible to link all three programs (cad, mesh, cfd)?

Regards,
Argyris

 

[Matthias Maasch 21]

Hi Argyris,

 

Well, this changes a few things. I think you can forget about the feature I mentioned :) and maybe also about the partially-parametric approach. A fully-parametric model will be the best choice for you. But the procedure remains the same.

 

- Import the IGES

- Trace the outlines

- Find a suitable curve for the particular profiles (Naca, FSpline, Generic Curve -- you can find these curve types in CAD > Curves)

 

Just a few hints:

 

- Please see this post for a sample SAE front wing: Front wing

- Please see this post for a sample F1 rear wing: Rear wing

- Please see this post for a simple wing meta surface: Wing

- In my opinion you should familiarize yourself with the FSpline curve (as it is a suitable curve for profile modeling) and also you should study the tutorial "Profile Design"

 

Furthermore, you can share your IGES file either here in the Forum (by attaching it to your next post) or if you don't want to share it in public you can send it to me via email: maasch@friendship-systems.com. This would allow me to give you some more detailed advice.

 

Regarding your other question about CAD-MESH-CFD coupling. Yes, CAESES is capable of bringing together all these steps if the other programs are able to run in batch mode. Please find this link as an example, where one of our engineers coupled CAESES with Pointwise for meshing and OpenFOAM for the CFD simulations. In order to learn about these things you can study the feature External Software and our "Integrations" tutorials. The procedure is basically the same, all controlled via the software connector:

 

- Sending input files, probably a STL file (in CAESES this is represented by a trimesh or solid object)

- Providing the necessary control files (script for meshing -- this should come from your meshing software)

- Receiving the Volume mesh

- Using the mesh in a SECOND software connector in CAESES as input for your CFD code

- ...

 

Unfortunately I don't know the meshing software you mentioned, but I will ask my colleagues if someone has already experience with this code.

 

Best regards

 

Matthias

[Ms. Argyris Apostolidis 0]

Thank you very much again Matthias,

i ll have a look on everything you suggested and i will contact you in case i have a problem.

Argyris

[Mr. Mattia Brenner 6]

Hi Argyris,

 

apart from the things Matthias has mentioned, in the upcoming version 4 of CAESES there will be an additional functionality to deform an imported geometry: the free-form deformation. It will, however, not be available for CAESES Free users. Which FSAE team do you belong to? We are already sponsoring two teams with the full version of CAESES, so if you are in one of them, you will have access to it. If you belong to another team, we could discuss some sponsoring arrangements, too. Additionally, as a student, you are also entitled to a free license of the full version (see here: https://www.caeses.com/forum/index.php?/topic/67-how-to-get-a-student-license/).

 

Cheers,

Mattia

[Mr. Quoc Bao Nguyen 0]

Hi everyone,

Very nice to see this topic, this one is everything I am looking for.

I already took Friendship Frame work student version, and already trained by tutorial, I also refered the SHIPFLOW tutorial.

I am trying to optimize one small ship that I am study but I have some problem as below:

When I run analysis the software wanning that FAIL and request me: Moving C:/Users/NTComputer/Desktop/off_dyne3-23.02/manual_results/baseline/comp/input/config to C:/Users/NTComputer/Desktop/off_dyne3-23.02/manual_results/baseline/comp//config

Moving C:/Users/NTComputer/Desktop/off_dyne3-23.02/manual_results/baseline/comp/input/off_dyne to C:/Users/NTComputer/Desktop/off_dyne3-23.02/manual_results/baseline/comp//off_dyne

I try to find the solution but...

Please help me to solve this.

Thanks in advance.

[Karsten Wenzke 12]

Hey Quoc Bao Nguyen,

 

Seems to be that you are trying to execute SHIPFLOW but you need a license for SHIPFLOW as well. Which is NOT included in the CAESES (former FRIENDSHIP Framework) student version.

Therefore you need to apply for a SHIPFLOW license as well.

 

Let me know if you need further assistance. If you do have a valid shipflow license I'd like you to attache the project file.

 

Cheers,

 

Karsten

[Mr. Quoc Bao Nguyen 0]

Thank you very much Karsten,

 

You are correct. Before I recieved Friendship I have had ShipFlow licence.

But seem shipflow didn't accept any IGES file from other software except from friendship framework.

I made a model by friendship aready and shipflow accept that one.

 

Unfortunatly, my shipflow is useless and I already remove Shipflow.

So, could you help me solve this problem Karsten? How can I optimize the hull form by Friendship?

 

Thank you very much.

[Karsten Wenzke 12]

Hey,

 

 

So, could you help me solve this problem Karsten? How can I optimize the hull form by Friendship?

CAESES is a CAE tool and has no CFD solver included.

You can model your ship and create various variants but for the optimization you need to have a CFD code.

 

 

You are correct. Before I recieved Friendship I have had ShipFlow licence.

But seem shipflow didn't accept any IGES file from other software except from friendship framework.

I made a model by friendship aready and shipflow accept that one.

 

Unfortunatly, my shipflow is useless and I already remove Shipflow.

 

I do not understand the problem. Why did you remove shipflow?

 

Cheers,

 

Karsten

[Mr. Quoc Bao Nguyen 0]

Thank you Karsten,

 

Firstly, I remove shipflow because I think friendship is include shipflow (Have optimization tool).

Secondly, after I install friendship, I can not open shipflow. Shipflow ask me about license many time and does not accept (The license received from shipflow). 1 guy supporter of shipflow advise me can use student version of friendship.

 

So, now I need to install shipflow again to solve this problem?

 

Thanks.

[Karsten Wenzke 12]

Hey,

 

Firstly, I remove shipflow because I think friendship is include shipflow (Have optimization tool).

 

Shipflow is not included in CAESES. CAESES includes Variation and Optimization algorithms but they need an external solver (tool) in your case Shipflow to get some results (resistance, etc) and then based on these results create another variant (design) and start shipflow again with the new variant .....

 

Take a look at this site and read it then it should be clear what is included in CAESES.

 

 

 

 

So, now I need to install shipflow again to solve this problem?

Yes because Shipflow is not included in CAESES therefore you need to install it first. 

Also you need to have a valid license to be able to use shipflow it needs to be placed somewhere in the shipflow installation folder.

Since you had Shipflow installed and used it I think you know where to place the license file.

 

When you have installed Shipflow you are able to use shipflow for your hull optimization.

The CAESES tutorial Shipflow CFD Analyses shows you how to couple CAESES and Shipflow (Step 7).

 

Cheers,

 

Karsten

[Mr. Quoc Bao Nguyen 0]

Thank you Karsten,

 

It's really helpful to me. If any, I will contact you and please support me again.

 

Thank you very much.

[Mr. Quoc Bao Nguyen 0]

Hi Karsten,

Now I can use Friendship with flowtech, but I have one problem as:

 

When I use off-file export from software, it can not run. Exactly I want to make resistance curve by variant speed with off-file.

This is out-put file, can you help me to check what happen with my off-file? https://drive.google.com/open?id=0B_3K49CpUpKbY0tQamNMbXpkeEU

I also check with other out-put file from tutorial, it's almost same https://drive.google.com/open?id=0B_3K49CpUpKbWkRMejExZUxfLVk

 

My off-file has 2 part: main and bow. Main part I use "h1gr" and bow prat I use "fbgr" in hull (ship type).

Hope that you can understand what I mean.

 

Many thanks in advance Karsten.

Best regards.

[Mr. Dong Jiang 1]

Dear Quoc Bao Nguyen,

 

I'm the support engineer of CAESES in China, I have experience using both CAESES and SHIPFLOW. I hope I can help you with your problem.

 

May I ask you how do you get your offset file? Do you generate it from IGS file ? Sometimes if there is something wrong with the offset file, then you can not run it with shipflow.

 

I'm sorry the google service is not available in China. It would be better if you can send your file or project to my email address. caeseschina@163.com

 

Regards,

Daniel 

[Mr. Dong Jiang 1]

Hi Bao,

 

I think your problem is you didnt give a reasonable value of your vessel speed. Have you tried again on your project? Does it work well?

 

Regards

Daniel