Q：why the particles' temperature don't rise?

MFiX
#1

Hello friends,
I have problem that the particles’ temperature don’t rise when i use mfix-dem(pure granular flow) to run a simulation with Enable energy equations on.
the geometry is below,

1
1916×608 46.9 KB

And ,i hope the cantboard’s temperature be 1200K, while the other walls stay the No-flux type.
so ,the particles should have a teperature rise when falling down from the board.----but it seems don’t work.
Is it the BC i set up wrong?
image
image1219×788 216 KB

1.mfx (14.5 KB)
geometry.stl (11.1 MB)

#2

Your Heater region overlaps the wall region, so you have a conflict in the BC. You need to separate the regions so the STL files don’t overlap. I would slice the wall region twice to get a wall region upstream of the heater and another wall region downstream of the heater.

#3

thinks a lot!!
Another question 1: Can Mfix take the geometry wall as the no-slip-wall automatically**(I mean as default)**, without set up manually???—if possible, we can only consider the BCs which we want.?
Another question 2: What is the different of the selection method-----Full/partial/slice???

#4

Hi.

Please not that this post has already been marked as “solved”. Please don’t add new, unrelated questions to solved topics. It makes it harder for us to keep track of what questions have been answered, and it makes it harder for others to search the forum when the topics don’t match the contents.

I don’t fully understand your question 1. All boundaries must have a defined type. In mfix/model/init_namelist.f you will find

     BC_TYPE(LC) = UNDEFINED_C

I suppose you could try changing this to BC_TYPE(LC) = 'NSW' and see what happens.

Regarding question 2; the answer to this is displayed in the ‘tooltip’ which appears when you hover the mouse over the relevant control.
shot-2022-03-24_09-31-51

Perhaps we should add this text to the user documentation.

– Chares