Viewfactor computation in axi symmetric modell

[carstenp]

Hi everyone,

I have a small problem computing viewfactors in an axi symmetric modell. When I use 2D cartesian coordinates everything works as expected. When I change the coordinate system to axi symmetric, all the view factors a zero.

Is there a reason for this behavior?

Best,

carsten

[raback]

Hi

When you choose axisymmetric coordinates then (x,y) is assumed to be (r,z). The symmetry axis is at x=0 and you should not have negative values in the system. Other than that they should work quite the same way.

-Peter

[carstenp]

Hi Peter,

thanks for the quick reply.

I found the problem. There was a boundary edge at x = 0 which was set as diffuse radiation boundary. Removing the edge solved the problem.

Just for clarification, the symmetry axis is always assumed to be at x = 0? So If I have a rectangle with x = [xMin,xMax] x > 0, the axi symmetric model be a cylinder shell with rMin = xMin and rMax = xMax?

Is there a way to manually specify the rotation axis?

carsten