Co-simulating - Temperature analysis

[KacoZago]

Hello

I simulated a interaction between an air layer (12 cm) and a concrete plate (12 cm). My doubt is:

1) The temperature gradient between the top face and the bottom face, of the air layer, shouldn't be smaller, after 75 minutes? (see Annex 1). I am finding a difference of 900 degrees.

I think, after a time, this air layer should have the same temperature, in top and the bottom faces. I expect to see it.



Boundary condition utilized in Air Layer:

- Inlet: Temperature = Furnace (see Amplitude)

- Outlet: Pressure = 0

- Co-simulation = Interface between air layer and concrete plate



Abaqus File (Plate.CAE): Link

Abaqus File (Plate.JNL): Link


Problem:

Annex 1 - AIR LAYER results:

 

[Mustaine3]

The temp of 965 is defined by your BC. So Abaqus has to apply that.

Air-Model -> BC Inlet -> Magnitude=1 with reference to an Amplitude.

 

[KacoZago]

Hello Mustaine3

I didn't understand your point. I did this.

My doubt is, after 75 minutes, why this layer (12cm) isn't uniformed? My point is, I expected to see a thermal gradient less than that found (900 degrees).

I simulated only the air layer (without the concrete plate). See the results below (5 and 75 minutes).

Fire test after 5 minutes - the air layer isn't uniformed.

Fire test after 75 minutes - the air layer is uniformed.

Now, I would like to model this air layer with the concrete plate

Best regards

 

[Mustaine3]

Yeah, you're right. Sorry.

I've no idea where the problem is. With your result I see only two possible errors. Either energy is lost in the interface or something is wrong with the material data of the concrete.

 

[KacoZago]

Hello Mustaine3

I thought the same thing. When we simulated the interface (Co-simulation), we didn't assign any value. Isn't it stranger?
I say this, because when we simulated the interaction between two materials, we defined the Conductance and the Clearance in contact.
Other doubt is, why this air layer doesn't have convection? What do you think?

I checked the material data of the concrete and of the air. Unfortunately, this isn't the problem.
I also checked the boundary condictions, but I didn't have success.

Thank you very much for your tips.
best regards