Solid Walls - Two approaches?

[CbsTau]

Hello,

I am modelling the flow generated by a rotating fan through a rectangular duct, and so I make the Side walls, and the Top and Bottom walls: TYPE_S

The problem then is that I cannot see into the box in shaded mode (VIS_FLAG_SURFACE).

Would it be the same numerically to model the solid walls of the ducting as follows:

	if(x==0u||x==Nx-1u||z==0u||z==Nz-1u) lbm.flags[n] = TYPE_E;   // Top and Side Walls set to Environment
	if(x==0u||x==Nx-1u||z==0u||z==Nz-1u) lbm.u[n] = 0.0f;             // Top and Side Walls velocity in x,y,z set to zero

This way I can see into the box to view the fan in shaded mode.

Is this approach equivalent numerically to setting the walls as TYPE_S?

Thanks in Advance!

[ProjectPhysX]

Hi @CbsTau,

(TYPE_S) and (TYPE_E with u=0) are not equivalent. Use TYPE_S here, that ensures mass conservation.
To be able to look into the box in VIS_FLAG_SURFACE mode, modify this line to

	if(xyz.x<=0u||xyz.y<=0u||xyz.z<=0u||xyz.x>=def_Nx-2u||xyz.y>=def_Ny-2u||xyz.z>=def_Nz-2u) return;

Kind regards,
Moritz

[CbsTau]

Hi Moritz,
Many thanks for this clarification and work-around for visualizing inside closed boxes.

Kind regards, Clinton