Temperature is not calculated

[capucine_lasserre2001]

Hi everyone, 

I'm trying to model an heat exchanger with the software. I tried multiple designs with the same bondary conditions ( Inlet temperature and mass flow for both fluids and gage pressure equals zero to create the oultet). Yesterday I modeled a new design very similar to the previous one (that worked fine) but perhaps a little bit more complex and when I lunch the simulation the temperature is calculated at all (does not show in the convergence plot). The heat transfer box is checked. I restarted the simulation (from the first iteration and from the last) multiple time  to see what would happen but it does not change. 

I really don't understand why it does not calculate the temperature. 

[capucine_lasserre2001]

Hi everyone, 

I'm trying to model an heat exchanger with the software. I tried multiple designs with the same bondary conditions ( Inlet temperature and mass flow for both fluids and gage pressure equals zero to create the oultet). Yesterday I modeled a new design very similar to the previous one (that worked fine) but perhaps a little bit more complex and when I lunch the simulation the temperature is calculated at all (does not show in the convergence plot). The heat transfer box is checked. I restarted the simulation (from the first iteration and from the last) multiple time  to see what would happen but it does not change. 

I really don't understand why it does not calculate the temperature. 

[marwan_azzam]

Hello @capucine_lasserre2001 ,

If the Auto Forced Convection is checked then the program won't calculate any temperatures until the flow calculations are done. If the temperature field does not effect the flow then you should have this box checked to make the analysis go faster.

If this box is not checked and you are still not getting any temperature calculations make sure the two inlet temperatures in the boundary conditions are not the same value.

Marwan

[marwan_azzam]

Hello @capucine_lasserre2001 ,

If the Auto Forced Convection is checked then the program won't calculate any temperatures until the flow calculations are done. If the temperature field does not effect the flow then you should have this box checked to make the analysis go faster.

If this box is not checked and you are still not getting any temperature calculations make sure the two inlet temperatures in the boundary conditions are not the same value.

Marwan

[capucine_lasserre2001]

@marwan_azzamthanks for the answer and yes I tried/checked  these two things but it still not working...

[capucine_lasserre2001]

@marwan_azzamthanks for the answer and yes I tried/checked  these two things but it still not working...

[marwan_azzam]

Hi @capucine_lasserre2001 ,

Ok. So what do we do next, 1 or 2?

1- I keep making guesses, or

2- You share your model?

Marwan

[marwan_azzam]

Hi @capucine_lasserre2001 ,

Ok. So what do we do next, 1 or 2?

1- I keep making guesses, or

2- You share your model?

Marwan

[capucine_lasserre2001]

@marwan_azzam Sorry, I thought the file was shared with the initial post...

You can find it under there if you want, but I opened another file with the same design and hypothesis and the temperature was calculated as usual! So I you can have a look into it so it does not happen again it would be great but no worries if you don't spend a lot of time on it. 

[capucine_lasserre2001]

@marwan_azzam Sorry, I thought the file was shared with the initial post...

You can find it under there if you want, but I opened another file with the same design and hypothesis and the temperature was calculated as usual! So I you can have a look into it so it does not happen again it would be great but no worries if you don't spend a lot of time on it. 

[marwan_azzam]

Not a problem.

Whenever you're ready to share the model I'd be happy to take a look.

Marwan

[marwan_azzam]

Not a problem.

Whenever you're ready to share the model I'd be happy to take a look.

Marwan

[capucine_lasserre2001]

It´s not shared under the last reply ?

[capucine_lasserre2001]

It´s not shared under the last reply ?

[marwan_azzam]

@capucine_lasserre2001 ,

Q- "It´s not shared under the last reply ?"

A- It´s not shared under the last reply.

You posted the following files:

- Design 1_model.log
- control.xml
- mesh.log

None of those are the model.

You need to share the model's support share file (*.cfz).

The *.cfz file cannot be shared as-is on the forum for some reason.

You need to zip the *.cfz file and post the *.zip file.

Marwan

[marwan_azzam]

@capucine_lasserre2001 ,

Q- "It´s not shared under the last reply ?"

A- It´s not shared under the last reply.

You posted the following files:

- Design 1_model.log
- control.xml
- mesh.log

None of those are the model.

You need to share the model's support share file (*.cfz).

The *.cfz file cannot be shared as-is on the forum for some reason.

You need to zip the *.cfz file and post the *.zip file.

Marwan

[capucine_lasserre2001]

ah thanks fot the tipes about the zip file, that's why it wasn't sharing ! Hopefully with this file we are all good?

[capucine_lasserre2001]

ah thanks fot the tipes about the zip file, that's why it wasn't sharing ! Hopefully with this file we are all good?

[marwan_azzam]

Hello @capucine_lasserre2001 ,

"Hopefully with this file we are all good?"

No, we're not.

You zipped and posted the *.cfdst file.

I specifically asked for the *.cfz file.

Let's try again.

Marwan

[marwan_azzam]

Hello @capucine_lasserre2001 ,

"Hopefully with this file we are all good?"

No, we're not.

You zipped and posted the *.cfdst file.

I specifically asked for the *.cfz file.

Let's try again.

Marwan

[capucine_lasserre2001]

how about now?

[capucine_lasserre2001]

how about now?

[marwan_azzam]

Hello @capucine_lasserre2001 ,

Thank you for posting the model.

I ran it as-is without changing anything and I am getting a temperature profile as seen in image below. The image shows the temperature through a cut plane perpendicular to Z.

I'm not sure why it's behaving differently on your end.

Did you let it run to completion?

Marwan

[marwan_azzam]

Hello @capucine_lasserre2001 ,

Thank you for posting the model.

I ran it as-is without changing anything and I am getting a temperature profile as seen in image below. The image shows the temperature through a cut plane perpendicular to Z.

I'm not sure why it's behaving differently on your end.

Did you let it run to completion?

Marwan

[capucine_lasserre2001]

@marwan_azzam , yes, i let it run until the end (as seen by the input on the message windows). I don't know what happened; let's hope it does not happen again; but I you didn't find the issue I think I should mark this conversation as solved and continue with a file that works? thanks again for the time and help!

[capucine_lasserre2001]

@marwan_azzam , yes, i let it run until the end (as seen by the input on the message windows). I don't know what happened; let's hope it does not happen again; but I you didn't find the issue I think I should mark this conversation as solved and continue with a file that works? thanks again for the time and help!

[marwan_azzam · Accepted solution]

@capucine_lasserre2001 ,

You are right. There was no problem with the model you posted so just use that.

Marwan

[marwan_azzam · Accepted solution]

@capucine_lasserre2001 ,

You are right. There was no problem with the model you posted so just use that.

Marwan