Outflow natural boundary when v.n is outward

Extension of Elmer in computational glaciology

Outflow natural boundary when v.n is outward

Postby denis.cohen » 26 Jan 2014, 20:58

Hello,

I don't want to impose a Dirichlet Temp BC when the surface velocity is out of the free surface (v.n >0) so I have this in my top surface BC:

Temp = Variable Coordinate 3
Real MATC "min(273.15 273.15-5.3-0.006*tx)"

Temp Condition = Variable Velocity 1 , Velocity 2 , Velocity 3, Normal Vector 1, Normal Vector 2, Normal Vector 3
Real MATC "Cond(tx)"


and this for Cond:

$ function Cond(tx) {\
dotprod=tx(0)*tx(3)+tx(1)*tx(4)+tx(2)*tx(5);\
_Cond=-dotprod;\
}


However, this does not seem to work. Actually the code stops without any warnings or error message.

Anybody has tried this before?

Thanks

Denis
denis.cohen
 
Posts: 55
Joined: 15 Dec 2010, 13:50

Re: Outflow natural boundary when v.n is outward

Postby tzwinger » 27 Jan 2014, 13:08

Denis,
it is odd that you do not get any error message. What I could think of is, that you perhaps dash into an issue if you evaluate this condition before the variables you need (Velocity and Normal Vector) have been assigned with a value, hence leaving the Temp Cond with Zero.

A
Code: Select all
Initialize Dirichlet Conditions = Logical False
in the Simulation section might help in that case.

Regards,

Thomas
tzwinger
Site Admin
 
Posts: 79
Joined: 24 Aug 2009, 12:20

Re: Outflow natural boundary when v.n is outward

Postby denis.cohen » 01 Feb 2014, 20:28

Hi Thomas,
Thanks for the info. It's running now. Will check results.
Denis
denis.cohen
 
Posts: 55
Joined: 15 Dec 2010, 13:50


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