sci.math.research
SUNA29, Linearized Quadrilaterals
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Two element types were developed as a Unified Numerical Approximation for Ideal
Flow: "Staggered Quadrilaterals" and "Patched Quadrilaterals". The former type
gives rise to the following set of equations for the quadrilateral as a whole:
3 (y2  y1).u1  (x2  x1).v1 +
4 o * o 3 (y3  y2).u2  (x3  x2).v2 +
  (y4  y3).u3  (x4  x3).v3 +
4 * * 2 (y1  y4).u4  (x1  x4).v4 = 0 (1)
  (x2  x1).u1 + (y2  y1).v1 +
1 o * o 2 (x3  x2).u2 + (y3  y2).v2 +
1 (x4  x3).u3 + (y4  y3).v3 +
(x1  x4).u4 + (y1  y4).v4 = 0 (2)
The latter type of ("patched") element resulted in linear relationships between
function values:
u1  u2 + u3  u4 = 0 (3)
v1  v2 + v3  v4 = 0 (4)
Isn't it possible to combine these four equations into the formulation of a new
Finite Element for Ideal Flow? That would be simple and straightforward anyway.
We tried just that ... And it seems to work! ^^^^^
More later. My vacation is over. Going back to regular activities.
Don't worry if you didn't catch up every SUNA article that appeared on the net.
I will make this stuff available via kind of Anonymous Ftp or Bulletin Board.
Alas, administratium is impeding a quick reaction here. :)

* Han de Bruijn; Applications&Graphics  "A little bit of Physics * No
* TUD Computing Centre; P.O. Box 354  would be NO idleness in * Oil
* 2600 AJ Delft; The Netherlands.  Mathematics" (HdB). * for
* Email: Han.deBruijn@RC.TUDelft.NL  Fax: +31 15 78 37 87 * Blood