Elmer Discussion Forum

I want to simulate the heat flow through a double pane window. I was thinking of trying to do this in 2D. The simulation will model night time heat flow. I want to include the effects of thermal radiation from both the night sky and the room interior. It looks like I might be able to do this with th...

If, in order to get convective conduction, I must turn on Navier Stokes, it would seem possible to turn it on in some bodies and not in others. The only bodies in which there is any flow is in the air. For the rest of the simulation there would be no material flow. However, It is a big deal as to wh...

I have been working on and off for a while now on my simulation of a winter greenhouse. I am pretty close to trying a run. Initially, I will be running just heat flow. I have a few questions before i do. 1) I presume that I have to set initial temperatures for all bodies. However, I don't know what ...

I am confused about how to define the surfaces that will be used to establish the volumes. Can surfaces be defines such that parts of that surface may be parts of another surface, or must all surfaces be non-overlapping? Imagine, for example, trying to define volumes for a ziggurat. Could you define...

Juha: I've looked at this HeatGap problem and I don't quite see what is going on. I ran ElmerGrid on the grid file and looked at the mesh. It almost looks like every cell is both a boundary of type 1 and 3. The exterior appears to be boundary 1. Can you say something more about this mesh? Thanks, bill

Peter-in-Finland: I agree and have always intended to model some depth of the soil. My intention was to assign a deep temperature earth temperature, say at 3 meters, and have the code determine the vertical temperature distribution. My reason for wanting to use the heat transfer coefficient can be a...

Peter: I'm happy to see that you think Elmer might be a better fit for the project, although I have downloaded and installed EnergyPlus. What is neat about it is that there is a possibility to use Google Sketchup to create the building and surface properties. I have not used this code but my 13 year...

Peter: It was to a question I put to you back in August, I think, that you are referring to. At that time you said that I could have an internal boundary condition using the heat transfer coefficient. My problem is, however, what to use for the external temperature input. It appears to be required f...

I am modeling a 3D building. it is embedded in a cube of air on the outside and sitting atop a layer of soil. I need to be able to model the thermal properties of the walls, roof, floor, and windows. My choices are to include in the mesh the associated thicknesses and associate the heat conductivity...

I want to simply model the effect of thermal insulation across an interface. Can I do this by using the Heat Transfer Coefficient boundary condition? This ought to be possible. It seems that alpha (heat transfer coefficient) ought to equal 1/(R*x), where x is the thickness of the material at the int...