Transient solar loading geometry

[Anonymous]

Hello,

I want to simulate comfort zone in a building made of normal concrete block under transient solar loading. The figure 1 represents a normal concrete block.

When the normal block is stacked over each other for the building façade construction, air pockets are trapped inside the façade due to the hollow geometry of the block. As shown in figure 2.

I want to know the transient heat transfer across this type of façade.

My question is,

How do I a create a proper geometry to simulate the above?

[Jon.Wilde · Accepted solution]

How about just using three layers of materials in the model? Concrete, air, concrete.

Should be pretty close to reality I think.

[Anonymous]

Thank you @Jon.Wilde. Very helpful.

I have perform the analysis. 

I followed a tutorial found on website of Autodesk. 

We had to create 2 volumes, one representing ground and another representing  the air environment.

However i am a bit doubtful about the parameters such as the emissivity which was set to 0.3, density, specific heat, transmisivity and conductivity for both volume.

i want to simulate a real situation. Can i have more insight about which value to choose for those parameter and how to set them.

Thank you in anticipation.

[Jon.Wilde · Accepted solution]

You are most welcome.

For the materials, I would lean towards the defaults.

What is the ground made of? Use Grass/Concrete for example. These are in the database.

For the air, I would again use the default emissivity of 1, so that any radiation simply exits where you have no other boundary condition.

I would think that the default materials are fine, do you think that any need to be changed for your analysis?

Thanks,

Jon

[Anonymous]

Hello,

I have use Soil dry Clay as ground material and set others as different variable air volumes. However i am getting "Solver exited unexpectedly". I have attached the CFX file.

I am not able to figure out what may be possibly wrong. 

Can you help me out.

Thank you in anticipation.

[Jon.Wilde · Accepted solution]

Have you tried without radiation to see if it works?

I might be a little over constrained with the wall temps, not totally sure yet though.

My guess is that you also need more mesh, this might actually solve everything 🙂

Also, run with Advection Scheme 5 😉

[Anonymous]

Thank you @Jon.Wilde.    I adjusted the mesh and activated advection scheme 5. The analysis was completed successfully. I have another query, does the setup include heat loss or gain by convection and conduction?

[Jon.Wilde]

No worries, you are most welcome!

Yes, conduction and convection are on as soon as you enable heat transfer 🙂