# MATLAB Application of wall boundary

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 October 17, 2016, 08:30 MATLAB Application of wall boundary #1 New Member   Join Date: Sep 2016 Posts: 3 Rep Power: 8 Hello friends, I'm currently working on my own solver of Eulers equations, using cell centered finite volume method with Maccormacks scheme. My domain is channel with circular bump (10% of height), and i have a problem with applying boundary condtition on bottom wall with that bump. I know i have to use formula vn = 0, however, i have no idea how to code it. On top wall it was no problem, since i just set the velocity in cell behind the wall to negative value of the velocity before the wall. So my question is how do i apply the vn = 0 on wall that is not straight? Hope my question makes sense. Sorry for my bad english. Any advice or reference will be welcomed. Have a nice day.

October 17, 2016, 09:21
#2
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Filippo Maria Denaro
Join Date: Jul 2010
Posts: 6,266
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Quote:
 Originally Posted by Jbsl Hello friends, I'm currently working on my own solver of Eulers equations, using cell centered finite volume method with Maccormacks scheme. My domain is channel with circular bump (10% of height), and i have a problem with applying boundary condtition on bottom wall with that bump. I know i have to use formula vn = 0, however, i have no idea how to code it. On top wall it was no problem, since i just set the velocity in cell behind the wall to negative value of the velocity before the wall. So my question is how do i apply the vn = 0 on wall that is not straight? Hope my question makes sense. Sorry for my bad english. Any advice or reference will be welcomed. Have a nice day.

Just as an example for a 2d problem, if you have a cartesian reference system you just set:

n.v= 0 = nx*u+ny*v -> u/v = -ny/nx

of course if you have also no-slip condition you must associate the tangential condition t.v = 0.

 Tags inviscid, matlab, wall boundary condition