KIVA (Wall boundary conditions)

Jazi · January 17, 2010, 17:16

Hi Guys
I try to run a gas flow in a duct in Kiva with uniform inflow boundary. When I apply the law of the wall as a boundary condition in kiva, the tangential velocity components are not zero at the walls, just the normal velocity is zero.
Also the average velocity is different in various cross sections.
I am wondering if any body has any idea about these.
Thanks

DaIN · May 11, 2010, 11:41

Hi Jazy,

I also had a similar problem before, since law of the wall condition doesn't work properly when you have a fine mesh.
To start with, I could recommend you to try either running the code with different boundary condition (free slip to check out what's going on) or to have a proper look at the law of the wall subroutine.
I tried to deactivate it when i run my code with very fine meshes, and at least the code doesn't crash.

hope it helps

January 17, 2010, 17:16	KIVA (Wall boundary conditions)	#1
Jazi New Member Join Date: Jan 2010 Posts: 1 Rep Power: 0	Hi Guys I try to run a gas flow in a duct in Kiva with uniform inflow boundary. When I apply the law of the wall as a boundary condition in kiva, the tangential velocity components are not zero at the walls, just the normal velocity is zero. Also the average velocity is different in various cross sections. I am wondering if any body has any idea about these. Thanks

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May 11, 2010, 11:41		#2
DaIN Member Join Date: Nov 2009 Location: United Kingdom Posts: 35 Rep Power: 17	Hi Jazy, I also had a similar problem before, since law of the wall condition doesn't work properly when you have a fine mesh. To start with, I could recommend you to try either running the code with different boundary condition (free slip to check out what's going on) or to have a proper look at the law of the wall subroutine. I tried to deactivate it when i run my code with very fine meshes, and at least the code doesn't crash. hope it helps