[trompethans]

Hi everyone,

In my geometry of a furnace I would like to simulate once just the diffusion with heat which is coming from the flame. So no fancy physical models.

Now I wanted to create the heat source in the middle of the geometry. Therefore I created a box in the geometry. In the 'region' settings, I set the temperature of the 'flamebox' at 2000K. In the boundary I was thinking about a wall boundary with the condition UDF=2000K.

However, my idea seems not to work. So I have two questions:
- Do I have to check a specific box or model to make sure diffusion is modeled?
- What is a smart way to implement such a 'flamebox': what should be the region and/or boundary conditions to make sure the box acts as a simple flame in the furnace?

Thanks in advance!

[trompethans]

In the CONVERGE manual I found that the UDF=2000K wall boundary should exchange diffusive heat. My region_0=300K and region_1=2000K initially.

In the Tecplot however none of it seemed to work: there is no diffusion at all and also the 'flame' idea has gone, since the whole geometry stays 300K at all time.

Can someone please help me out?

[crajath]

Hello,

All you have to do is make sure you select the 'Solve internal energy' option under Run Parameters > Misc > Energy Solver. Diffusion should always be modeled while solving the energy equation.

Have you considered using the Energy sources available in CONVERGE instead of the 'flamebox'? This should help with what you are looking to do.

[trompethans]

Thanks! Diffusion energy solver is on. I will use the source function now, that's a better idea!

[trompethans]

I used now the source modelling with these settings:
- Source: energy
- Source units: energy/(m3 s)
- Value: 35.600.000 (combustion heat of methane)
- Max temperature: 2500 K
- Mode: sequential (2.0-10.0 s)
- Shape: box
- Motion: stationary

However, I get now four "BAD TERMINATION" errors... Memory (RAM) usage is not high, no other processes are opened at the same time. Also, it doesn't run on other hardware as well, so that's not the problem. And finally, CONVERGE did run perfectly before adding the source, so the problem should be there. (in the log.out, the source.in file is indeed the last file checking when the error occured...)

I hope some of you can help me - I attached the files in this post, so you can check it out on your own computer if needed.

[crajath]

Can you send an email to support@convergecfd.com (US); supportEU@convergecfd.com (EU) or support.in@convergecfd.com (India) with the case setup and a description of the problem? We can take a look

[trompethans]

Thank you for replying!

I just sent al the files, hope you can help