Hi.
I m trying to solve hagen poiseuille flow in matlab but not able to get the result.
Can anyone help me…how i can apply Axisymmetric Conditions in LBM.
You need to copy your populations to boundary node to fulfill symmetric conditions, i.e.
if your symmetry condition is in x direction the d_n U_{x}=0, U_y=0 at wall. I usually copy populations on the wall from the fluid node (after collision) in the certain order,i.e.
2
6 ^ 5
|
3<—0---->1
|
7 v 8
4
FFFFFF ____(symmetry plane)
BBBBB
f_{B,0}=f_{F,0}
f_{B,1}=f_{F,1}
f_{B,3}=f_{F,3}
f_{B,2}=f_{F,4}
f_{B,4}=F{F,2}
f_{B,5}=f_{F,8}
f_{B,8}=f_{F,5}
f_{B,6}=f_{F,7}
f_{B,7}=f_{F,6}
In this case macroscopic BCs are fulfilled. As well you don’t need to copy all population you only need to define populations pointing into the domain (F_{B,2,5,6})
Hopefully it will help,
Alex