[dfa]

Hi,
Does anybody know if there is any information out there that will help me with implementing this model? I am not really sure where to look. I am a student and so I do not have access to StevePortal. Any help will be appreciated.
Thanks

[profi_star-ccm+]

Originally Posted by dfa

Hi,
Does anybody know if there is any information out there that will help me with implementing this model? I am not really sure where to look. I am a student and so I do not have access to StevePortal. Any help will be appreciated.
Thanks

This model is easier to calculate on a calculator.
Do it differently: create a 3D model of the propeller-fan and using the overset mesh, start the calculation with realistic accompaniment, tying it to a ship or an airplane. There will be more cells, but it will be nice and accurate.

[fluid23]

The help files are installed with the program are an excellent place to start. There are several options and the one you choose will depend on what you are trying to model.

Simcenter Star-CCM+ > Simulating Physics > Virtual Disk Model

There are also some tutorials (also part of the install) that demo some of the more complicated modeling options.

Tutorials > Motion

All due respect to Aleksandr, but I don't think you have provided enough details on what you are trying to model for anyone to give you advice on what to use or how to approach it. I personally would not spend the computational resources to model an 3D overset mesh unless I needed the level of fidelity it provides.

What exactly are you trying to do?

[dfa]

Originally Posted by fluid23

The help files are installed with the program are an excellent place to start. There are several options and the one you choose will depend on what you are trying to model.

Simcenter Star-CCM+ > Simulating Physics > Virtual Disk Model

There are also some tutorials (also part of the install) that demo some of the more complicated modeling options.

Tutorials > Motion

All due respect to Aleksandr, but I don't think you have provided enough details on what you are trying to model for anyone to give you advice on what to use or how to approach it. I personally would not spend the computational resources to model an 3D overset mesh unless I needed the level of fidelity it provides.

What exactly are you trying to do?

Hi Matt,
Thanks for your response, what I am trying to do is represent a helicopter rotor as a virtual disk. I plan on using the blade element method to do this. I would appreciate any guidance on how to setup and mesh this model. On a related note, for the blade element method it asks me to input a .c81 file to get the airfoil sections but I only have an excel file. Is there any way to convert to .c81? Many thanks.

[fluid23]

It's been a while since I used the blade element model, but I recall uploading tables of span, chord, twist, airfoil properties and then linking to those. I believe I used a *.csv file to do that which can be generated with a 'save as' operation in Excel.

Looking at the relevant help file page, it looks like there are two table format options File Table and C81. I am not familiar with C81 table, but if you have an excel file, File Table is the probably way to go. See:

Simcenter Star-CCM+ > Simulating Physics > Virtual Disk Model > Blade Element Method > Specifying the Airfoil Sections

That being said, there is a rotor/fuselage interaction tutorial that I would recommend. I believe that iy also uses the File Table and covers disk mesh refinement and other things that you will find useful.

[dfa]

Originally Posted by fluid23

It's been a while since I used the blade element model, but I recall uploading tables of span, chord, twist, airfoil properties and then linking to those. I believe I used a *.csv file to do that which can be generated with a 'save as' operation in Excel.

Looking at the relevant help file page, it looks like there are two table format options File Table and C81. I am not familiar with C81 table, but if you have an excel file, File Table is the probably way to go. See:

Simcenter Star-CCM+ > Simulating Physics > Virtual Disk Model > Blade Element Method > Specifying the Airfoil Sections

That being said, there is a rotor/fuselage interaction tutorial that I would recommend. I believe that iy also uses the File Table and covers disk mesh refinement and other things that you will find useful.

Thanks Matt,
I'll try saving the excel file as a .csv and see what happens. I do not have access to these tutorials or files as I have a university license. Is it a PDF? If it is is there any chance you could send it to me? It will be very much appreciated. Once again, thank you for your help.

[fluid23]

The tutorials are in the help files. The corresponding .sim files are saved as part of the installation on your computer and the tutorials will walk you through how to find and open them.

If you cannot find the tutorial files, talk to your system admin. They come with every star-ccm installation.

You can access the help files under the help menu at the top.

[Asmaa Bahaa]

I can't understand this error . what should I do to solve it ?

[profi_star-ccm+]

Originally Posted by Asmaa Bahaa

I can't understand this error . what should I do to solve it ?

To use a virtual disk, you need certain knowledge that you do not have. The tutorial will not help in this case. There is one simple solution, but this is a very approximate or even far from the truth. It is used when they do not know how to use other features of the CFD, or when a weak PC, very weak. The economy must be economical. Fortunately, this is not my path and there is nothing to add.

[fluid23]

What error are you seeing? I suggest starting a different post with more information on your error, what you are trying to do and so on.

Refer to the this guide first, you will be more likely to get a good response if you follow these suggestions.

[Aeronautics El. K.]

Originally Posted by profi_star-ccm+

To use a virtual disk, you need certain knowledge that you do not have. The tutorial will not help in this case. There is one simple solution, but this is a very approximate or even far from the truth. It is used when they do not know how to use other features of the CFD, or when a weak PC, very weak. The economy must be economical. Fortunately, this is not my path and there is nothing to add.

There is evidence to suggest that the blade element method on many cases yields comparable results to a sliding mesh method. Not always, but comparable many times.

Also, even if one has access to hundreds or thousands of cores, it is still not necessary to use the most complex model ever to get the answer if a simpler model can give you the answer in a fraction of the time with acceptable loss of accuracy. At least in an industrial setting where organisations need to provide (or get) solutions within given timescales and be profitable.

[profi_star-ccm+]

Originally Posted by Aeronautics El. K.

At least in an industrial setting where organisations need to provide (or get) solutions within given timescales and be profitable.

I quote: "To each according to his needs and from each as possible."