Hello,
Thanks for explaining the plate in an oven scenario, that makes sense. Is the air in the oven being heated due to a heating element in the bottom of the oven? One possibility is something like a home cooking oven, with a bottom electric heating element in a closed cavity without a fan. Another possibility is an industrial batch heating oven, with heated air being circulated with a fan.
If it is a home cooking oven situation, is radiation from the bottom electric heating element a factor for you?
Just curious, it helps to know what physical arrangement is being investigated.
Rich.
Temperature Dependent Convective BC for Conduction
Re: Temperature Dependent Convective BC for Conduction
Hello again,
Take a look at a similar forum post, it may be helpful for you:
viewtopic.php?t=7865
Rich.
Take a look at a similar forum post, it may be helpful for you:
viewtopic.php?t=7865
Rich.
-
- Posts: 24
- Joined: 04 Apr 2012, 23:17
- Antispam: Yes
Re: Temperature Dependent Convective BC for Conduction
Thanks for sharing the code!
-
- Posts: 24
- Joined: 04 Apr 2012, 23:17
- Antispam: Yes
Re: Temperature Dependent Convective BC for Conduction
My model is related to an industrial oven. There isn't a radiative component to it. Its all conduction with a convective BC.
Thank you for the reference to the Mcguirre post. That post moves around a bit but in the end it appears to be a computed convection problem involving an N-S solver. I'm just need to use a simple convective BC. No CFD is involved with this approach.
Thanks!
Thank you for the reference to the Mcguirre post. That post moves around a bit but in the end it appears to be a computed convection problem involving an N-S solver. I'm just need to use a simple convective BC. No CFD is involved with this approach.
Thanks!
-
- Posts: 2237
- Joined: 25 Jan 2019, 01:28
- Antispam: Yes
Re: Temperature Dependent Convective BC for Conduction
One approach to consider is to include the gas around the plate in the model, still using heat equation only. The external boundary temperature can then be a variable of time and the heat conduction material property of the gas can be a variable of time.
Attached is a study
Attached is a study
-
- Posts: 24
- Joined: 04 Apr 2012, 23:17
- Antispam: Yes
Re: Temperature Dependent Convective BC for Conduction
That's an interesting work around. I need to think about that more.Seems like one would want to make the hypothetical gas very dense and with a very high specific heat. So far I evolve your idea into tricking it by adding another layer of a solid that has properties of hc and T infinity rather than going to a fluid. I'm having a LITTLE better luck with solids.
Here's a wild one for your consideration.Without delving into the internals of Elmer: What about calculating heat flux for each time step from hc (Tsolid-Tinfinity). The hc and Tinfinity would be given in tables in the sif or external files and Ts would be pulled from the model for a previous time step. That calculated heat flux would be a BC for the current time step. I wondered if that is what the Manual was suggesting?
I appreciate your help. Your efforts are greatly appreciated!
Here's a wild one for your consideration.Without delving into the internals of Elmer: What about calculating heat flux for each time step from hc (Tsolid-Tinfinity). The hc and Tinfinity would be given in tables in the sif or external files and Ts would be pulled from the model for a previous time step. That calculated heat flux would be a BC for the current time step. I wondered if that is what the Manual was suggesting?
I appreciate your help. Your efforts are greatly appreciated!