Sobol Sequence

[Mr. Suraj Pawar 0]

I am trying to optimize the propeller geometry. I came across a paper "An Optimization Process for Propeller Design and its Application Based on CFD" which uses CAESES and StarCCM+ for optimization. I would like to know if there are any tutorials on Sobol sequence?

 

How exactly does Sobol sequence works? Does the Sobol algorithm generates sequence of n points uniformly distributed in a space at the beginning? Or does the sequence of n points depends on CFD simulation results on previous iteration?

 

Thank you. 

[Mr. Mattia Brenner 6]

Hi Suraj,

 

the Sobol sequence is not dependent from previous CFD results. Hence, all designs of a Sobol study can be generated at the beginning and computed afterwards.

 

See also this: https://en.wikipedia.org/wiki/Sobol_sequence

 

Cheers,

Mattia

[Mr. Suraj Pawar 0]

Hello Mattia,

 

Is there any I can save .step file of all the geometries created by Sobol sequence? I can view all geometry variants in design viewer. How can I export all the possible geometries?

 

Thanks.

 

Best Regards,

Suraj Pawar

[Ceyhan Erdem 14]

Hi Suraj,

 

When you run any optimization sequence, the geometry for each new design will be automatically saved in the corresponding folder structure with respect to the export type defined previously in the Software Connector phase.

 

Say you are running a Sobol sequence; let's say the first created sobol sequence is Sobol_01

Within your CAESES project folder,

 

In the folder;

01_sobol / Sobol_01_des0000 <depending on the design, let's pick the first one> /Runner

 

You will find the geometry that you are seeking for.

 

Cheers

Ceyhan

[Mr. Suraj Pawar 0]

Hello Ceyhan,

 

I  have created a software connector. But currently I am not using external software. I am interested only in getting the geometry in .step format and not run the whole optimization in CAESES framework. I can run the sobol sequence and it generates 10 geometries. I am having two problems:

1. I can not view all the designs in design viewer

2. When I run the connector 01_sobol / Sobol_01_des0000 <depending on the design, let's pick the first one>/Runner folder is not created.

 

Can you please take a look into the attached file to see what is the mistake that I am doing.

 

Thank you very much. 

propeller_PD=0.8_highTipThickness.zip

[Ceyhan Erdem 14]

Hi Suraj,

 

2) Please use the command below,

 

 

[03_solid|Propeller.exportStarCcmPlusStep(getDesignDir() + "/propeller.step")]

 

Because you have not assigned any Software Connector; no geometry will be exported unless you specify explicitly.

 

You have to use this command in your Design Engine's "Design Pre/Postprocessing" menu, under the Postprocessing Commands.

 

So after the creation of each new design, the command to export the geometry to the relevant Design Directory will be executed.

 

1) In your setup, there was no objective assigned.

 

Please review the attached project and the picture.

 

Cheers

Ceyhan

propeller_PD_0.8_highTipThickness.fdbc.tar.gz

[Mr. Suraj Pawar 0]

Hello Ceyhan,

 

I was able to export the step file of the geometry created in Caeses. I would like to know if it is possible to have different name given to each of the exported step file. For example this command [03_solid|Propeller.exportStarCcmPlusStep(getDesignDir() + "/propeller.step")] will save each file as propeller.step. How can I have different names for each geometry. 

 

Thank You. 

[Jörg 29]

Hi Suraj,

 

You can try to create a string parameter (CAD > parameters > string parameter) which is an expression of the design ID or name (e.g. getCurrentDesign().getName()) and the base name (e.g. propeller_design_001.stp). This parameter can then be set as input for the post-processing commands, together with the design dir expression etc. No limits :-)