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-   -   Baffle cell problem in shock tube (http://www.cfd-online.com/Forums/cd-adapco/54166-baffle-cell-problem-shock-tube.html)

AB November 14, 2004 13:47

Baffle cell problem in shock tube
 
Hello,

I am trying to run a shock tube model, with a tube divided into 2 sections and each section is defined as different material( though air in both) but with different pressures and temperatures. I have given them stagnation inlet BCs and and pressure outlet BCs and slip walls and symmetry BCs on rest of the sides accordingly. I have also initialised the pressure and temp through Nav center from the initialisation option for different material.

Here all checks are completed without any errors but when I write the geometry file I get this error in the model::

Error 5 - "Adjacent cells are in different fluid streams and not seperated by a wall or baffle. "

This is where I dunno whether I need to specify baffle cells or not in the interface.

Also if I specify baffle then, it will become 2 seperate regions and there might then be no interaction between different fluid streams.

waiting for anyone's response...

I am sure many people here have done shock tube problem using star-CD and I want to get some tips and tricks .

Thanks,

AB

Brian November 14, 2004 14:04

Re: Baffle cell problem in shock tube
 
Your problem is that you have used two different materials. Materials are not allowed to mix, they must be in separate streams or be solid / fluid.

Specify the air in both sections as the same material, and problem solved. You would have to use user coding or perhaps tables to initialize.

AB November 14, 2004 16:32

Re: Baffle cell problem in shock tube
 
Hello Brian,

Still it is not working. I am getting all 0 values in my run and it says there are some warnings in .info file.

If u have time then please send me your email id so that I can send you the model file in zip format for you to just look into it as it is some simple error which I am not able to take care of.

Will be waiting for response,

Thanks,

Arnab

Brian November 15, 2004 02:51

Re: Baffle cell problem in shock tube
 
You should be sending it to your local support office for help.

Anton Lyaskin November 15, 2004 09:44

Re: Baffle cell problem in shock tube
 
Hi Arnab

You have to use different cell types and one material. To assign different initial temperature and pressure basing upon different cell types you'll have to use user subroutine INITFI

Regards, Anton


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