[Nek5000-users] Representing Curved Side in any plane

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

Michael,

I've only recently added general purpose midside-node support,
which puts a point in 3-space for any one of the 12 edges and
nek then fits a parabola to this.

I'll set up an example that demos this.  The feature has limited
support at the moment -- but does work in nek5000 and generates
correct geometry.

Depending on what you are after, there may be other ways to
generate the geometry.   One of my favorite techniques is to
project a given input geometry onto the desired surface.


Paul



On Sat, 27 Mar 2010, nek5000-users at lists.mcs.anl.gov wrote:



  Hello Users,




  My question is in regard to the curved side data section in the REA
file.  I know that the first 3 terms describe the side, element, and
radius, but there are several other numbers that are currently zero, and
then the letter C.



  Background for the question: I have a situation where I would like to
curve an element edge in any plane. I know this is possible from
previous posts regarding a sphere.rea.



  I know that with two points and a radius, that is enough to describe a
circle in a plane.  But lets say I have a side where 2 pts lie on the
XY plane, but the center of the circle is located on the YZ plane for
example... the question is how to represent this in the REA. In the REA
you just give the element side ( 2 pts ) and the radius, which does fix
the circle center but the plane that contains the center is not
fixed.  So what I am wondering is what the other numbers in this
section do...if you could say, give the center instead of the radius, or
give a third point with the other 2 pts in the element side to fully
define the circle and plane.



  Also, Is it possible to curve the remaining 4 sides of the element
(edges 9, 10, 11, 12 that would be in the "z" direction) in the same
manner as edges 1-8? Thanks for any input on this matter!



  Regards,

  Michael Meador