Step-by-Step Tutorial: Session 3


#21

@jousefm and @radenpm9 - Automatic snappyHex for internal flows was renamed to Hex-dominant automatic for internal flow (CFD). Thanks for pointing that out, I’ll update the tutorial to avoid confusion!

see: Farewell to snappyHex - it has been renamed Hex-dominant mesh

Best,
Anna


#22

Hi @jousefm,
thanks for your reply. Then there is some difference between numerics in tutorial and yours. I uses yours (I think they are better anyway) and my simulation converged after about 200 minutes. In my first case I used the tutorial numerics and the convergence curve was very smooth, bur the convergence was too much slow.
One problem: the result of the first simulation is completed (I have the results) but there is an error (the bar is red!!)

cheers Luca


#23

Hi @l_trefiletti,

you cannot say in general that mine is better (I would rather say that the options Milad choses are better because he has way more experience than I have). The approach to verify this “better or worse” issue would be a benchmark and see which simulation gives us the best results.

Concerning your error please try it with the simulation properties Milad has given in the description.

If you still cannot manage to finish your simulation contact me again.

P.S: Make sure you set up your boundaries in a proper manner!!!

Cheers,

Jousef


#24

Hi @jousefm,
unforunately I have the same problem.
I meshed again the component (passive) and set up the boundaries again for a new simulation, I think in proper manner, but the simulation is slow and didn’t arrive to the convergence ( the time exceeds), but the convergence plot is smooth!!
this is my link project : https://www.simscale.com/workbench?publiclink=bfdf3c9b-c9af-4c40-927f-71e67f02c3de

could you check please?

thanks

Luca


#25

Hi @l_trefiletti,

checked your profile and noticed that your boundary conditions in the section “Walls” are wrong! Check them again and make sure you do not assign two boundary conditions for the same entity. Try it again and let me know how it worked :wink:

Cheers,

Jousef


#26

Why only in the 2nd Simulation (with fan), in the Numerics it’s explicited the reference pressure value of 101325 ?


#27

The 2nd simulation of mine also converged before the 2000th step. I had to lower the U and p residuals requested to reach t=2000. But since in this way the simulation at that final time is still not converged with the renewed and more strict residuals, I had also to change the write interval step not to risk to have no results written at t=2000.


#28

Hi @gned,

Make sure your boundaries are set up correctly!

Good Luck,

Jousef


#29

hi @jousefm,
I think I was careful, but my first simulation is sleeping… and in your simulation the board plate is in WALLS BC!!!
WALLS is= all faces element - board - chip1 - chip2 - inlet - outlet, right or not??

I used topological entities to be clear…

cheers Luca


#30

Hi @l_trefiletti,

neither inlet, outlet nor the chips1/2 are walls in my boundary “Walls”. With my settings I get the same results as Milad (at least in my passive cooling, did not adapt my settings in my active cooling - so treat with caution! ;))

Cheers,

Jousef


#31

@l_trefiletti - indeed you are correct on this

It appears the wall set still includes chip1 and chip2 (for simulation_passiv_bis)


#32

thanks for your help
I fixed (finally) my problem…and simulations are over!!!
thanks

cheers Luca


#33

and thanks @jousefm
cheers
L.


#34

Hi @l_trefiletti,

Was it the boundary setup?


#35

hi @jousefm,
there was a double set up for chip1/2.
L.


#36

That’s what I thought.

Glad everything worked well :slight_smile:

Cheers,

Jousef


#37

Hi everyone!
When will we get the results for the homework assignments?

Have a nice weekend! :slight_smile:


#38

Hello, I completed the homework assignments for the Maker course and on time but have not yet received the certificate. Thank you for your help.


#39

@jhorv_th and @aavalo2, we’ve received your homework and will be sending out the certificates this week so keep an eye out for an email from us!

Best,
Anna


#40

I’ve received it. Thank you! :slight_smile: