[Getdp] Second order element peculiarity
John_V
jvillar.john at gmail.com
Tue May 25 00:56:05 CEST 2010
While searching for an answer to my problem getting a 2nd order
electrostatic calculation to work
(http://geuz.org/pipermail/getdp/2010/001304.html), I ran across this
now several year old thread
(http://www.geuz.org/pipermail/getdp/2006/000868.html) that bears on the
problem.
All parties seemed satisfied with the solution, but I have run it
myself, and I am not so sure. When I run it, it appears to me that the
solution produced there is not second order. Here is my test: Upon
completion I open the options, go to View[0], select Iso-values with 101
intervals. This plots contours of constant potential from 0 to 100 V
with 1 V increments. Now zoom in on any of the elements in the solution.
What I observe is that the spacing between contours is constant within
elements. This is characteristic of a constant slope, i.e., the
potential is linear with position within each element. For this problem
the slope should decrease (contour spacing increase) with increasing
radius (i.e., to the right). It does, but the changes are all abrupt
ones only at element boundaries. A second order solution should be able
to describe slope changes within an element.
So why don't I see that? Is it something about my installation, or do
others get the same?
John