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sshoeb42
Posts: 17
Registered: ‎11-26-2012

concentration calculation from general scalar simulation

197 Views, 3 Replies
09-16-2013 09:52 AM

Hi Guys,

 

I am trying to study the fluid 1 displacement by fluid 2 using general scalar simulation for a given volume. I have few questions as follows

 

1. for a given boundary conditions the given volume should be filled in 0.011 sec but when i run it. it takes around 0.05 sec. I dont know why it is taking so long time. can anyone explain.

 

2. How to calculate the volumes of fluid 1 and fluid 2 after iam done with my simulation using scalar value. or may be concentration of fluid 1 and fluid 2.

 

Thanking you,

Shoeb.

 

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wildej
Posts: 960
Registered: ‎08-25-2011

Re: concentration calculation from general scalar simulation

09-18-2013 02:33 AM in reply to: sshoeb42

Hi Shoeb, 

 

I can try to help you out here.

 

  1. What are the fluids and what value are you using as the diffusion coefficient? Do you have Intelligent Solution Control turned on or off?
  2. I will have to leave this one to someone else as I do not think we can actually do this. We can meausure the scalar (which you can convert to concentration by hand) on a cut-plane but I'm not sure we can give you a ratio within the fluid volume.

Hopefully that helps you a little and with some more information on point 1 we might be able to help more.

 

Kind regards,

Jon



Jon Wilde
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Contributor
sshoeb42
Posts: 17
Registered: ‎11-26-2012

Re: concentration calculation from general scalar simulation

09-18-2013 07:36 AM in reply to: wildej
Hi Jon,
 
I took Fluid 1 (air) and fluid 2 (co2) I used the diffusion coefficient recommended i.e., 0.16 cm2/sec. when I used to run the simulation before without using scalar calculation i.e., just for flow calculations I didn't have problem with divergence. but when I started simulating the scalar simulation I had divergence in solution after some time so i have to reduce the vel, pressure, density to 0.4 from 0.5 and also reduced scalar from 1 to 0.9.
 
I tried running with both intelligent solution control turned on and off. The only difference I found between two that the former stops when the convergence is reached before the time I want it to run I changed to stricter but the convergence reached before the time I told it to run.
 
 
Can you just explain how to measure the scalar by hand
 
Thanking you,
Shoeb.
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Product Support
wildej
Posts: 960
Registered: ‎08-25-2011

Re: concentration calculation from general scalar simulation

09-18-2013 07:52 AM in reply to: sshoeb42

Hi Shoeb,

 

You can capture the scalar on a cut-plane and should be able to convert it to a concentration just using the ratio of Air to CO2. As far as I know, there is no way to do this per volume.

Happy to take a look at your CFZ (support file) if you think it might help.

 

Thanks,

Jon



Jon Wilde
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