[Nek5000-users] implement pressure and velocity BC

[nek5000-users at lists.mcs.anl.gov]

Hi Neks,

I've seen that it is possible to impose BC to a scalar variable in the 
.rea file with

***** SCALAR 1  BOUNDARY CONDITIONS *****

I want to defie something like Ux=Uy=0, dUz/dx=b, grad(p)=a. If I impose 
v in

***** FLUID   BOUNDARY CONDITIONS *****

I can then define Ux, Uy, Uz BC in the userbc subroutine. But, how can I 
define the BC in the pressure field? I've tried imposing outflow 
condition in

***** SCALAR 1  BOUNDARY CONDITIONS *****

Thus, I've copied all the BC defined in Fluid BC, and I've changed v by 
O.

However, it doesn't work.

What can I do?

Is there any way to say Nek5000 that I'm going to define velocity and 
pressure BC in the userbc suroutine?

Thank you.

SL




El 03-11-2014 17:56, nek5000-users at lists.mcs.anl.gov escribió:
> Hi Neks,
> 
> I'd like to use some specific function to define boundary conditions
> for pressure and velocity in my simulation.
> 
> For example, I'd like to use for velocity Ux=Uy=0 dU/dz=a, and for
> pressure grad(p)=b. I've seen that in usercheck it is possible to
> write time dpendent functions to define the boundary conditions for
> velocity. But, is there any way to write Neumann boundary conditions
> for pressure or velocity? Or to write the function that I want?
> 
> Thank you in advance.
> SL
> 
> 
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users