Hoi,

I tried to reactivate an older model in OGS5 for calculation of heat

transport in a 3D geometry. The model setup includes a Neumann (flux)

boundary for a cylinder surface.

For definition of the cylinder surface the old gli file included

#SURFACE

$NAME

CAN_CYLINDER

$TYPE

100

8 55 0.475 0.001

; point id for Center of top surface of cylinder, point id for Center of

bottom surface of cylinder, radius, epsilon

The definition of the cylinder surface does not work anymore, it only

defines the cap of the cylinder. It seems related to some kind of

replacement of Wenqings older routines where the case type 100 is not

included anymore.

I attached a picture of the mesh geometry and the cap surface marked

with a higher temperature (but I need the other cylincer surface as well).

Next I would like to set a Neumann (flux boundary) condition via the st

file. I hope at least that this will give a Neumann boundary condition

and not a simple source term as stated in the online help.

So this are actually the questions I have:

1) Is there another way to define the cylinder surface?

2) Does the CONSTANT_NEUMANN keyword in the st-file set a Neumann

boundary conditon, or simply a scaled source term?

2a) How do I set a Neumann boundary condition, if CONSTANT_NEUMANN is

for source terms only?

Thanks for the help and many greetings, Georg

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PD Dr. Georg Kosakowski * Laboratory for Waste Management

Paul Scherrer Institut * 5232 Villigen/PSI * Switzerland

Phone: +41-56-3104743 * Email: georg.kosakowski@psi.ch

homepage: http://www.psi.ch/les/georg-kosakowski