Greenhouse convection multiplier?

I’m wanting to study the extent to which convection force can be increased with a roof plane placed above the vents of a greenhouse. I need to see the potential air flow and temperature differential both inside the greenhouse as well as the ‘external’ flow taking place under the roof plane. The greenhouse is not the only relevant volume. There’s a residental space attached to it with the intent the greenhouse generated convection draws cooler ait into the living space. It’s complicated I suppose and in any case I can’t find a public project to use as a starting point. I need to understand the heat transfer through the glass of the greenhouse and the thermal mass quality of the solid walls as well as the effect of the sunlight heating of the roof… whew!

Hello, thanks for posting on forums.

Based on your description, I believe you are interested in working with the flow region in the surroundings of the building, so this would take an “External flow volume” operation as a starting point.

For example, it would be an operation similar to this one, in CAD mode:

Now, here are some pointers:

  • I’d personally suggest using a convective heat transfer analysis, since it’s a more simple approach to take. This analysis requires you to delete all solid parts of the domain (see the second image in this post). Again, after deleting the solid walls, the set up would be very similar to this project.
  • If you go for a conjugate heat transfer simulation, you can have the solid walls in your geometry, however you have to be cautious with mesh size and runtime. Since this approach is rather uncommon, there are no tutorials showing all the steps, so I would suggest that you run through this CHT tutorial before working on your project.
    These thermal bridge validation cases might also be relevant.
  • PS: a solar load functionality will be implemented soon, however it’s currently not available. Also, it only supports fluids at the moment - so the solid walls would need to be deleted.

Finally, posting the “delete body” operation that is required for convective heat transfer/solar load simulations:

Once you export the model (step 4 above), it should look like this:

Again, my natural convection project should be very similar, in terms of setup.