Changeset 637

Timestamp:

Nov 30, 2004, 2:27:21 PM (20 years ago)

Author:

ole

Message:

 

File:

• inundation/ga/storm_surge/wiki/issues.txt (modified) (2 diffs)

inundation/ga/storm_surge/wiki/issues.txt

@@ -4 +4 @@
 
   
-Issue: Segments is pmesh used to separate regions 
+Issue: Segments in pmesh that are solely used to separate regions 
 (e.g. for different resolution) will appear as an *internal* 
-boundary in the resulting domain even though it isn't intended to have a boundary condition applied.
+boundary in the resulting domain even though it may not have been intended to 
+have a boundary condition applied.
 Background: Genuine internal boundaries are created the same way as 
-external boundaries through the 'boundary' dictionary mapping triagle_id 
+external boundaries through the 'boundary' dictionary mapping triangle_id 
 and edge number to a tag.
 When a mesh is created, this dictionary will override the neighbour structure 
 and thereby enforce the internal boundary status.
-However, once a segment belongs to a boundary (internal or external) it must be bound to a boundary condition object in order to supply values for the 
-flux computations.
+This is all very well for 'True' internal boundaries.
+However, once a segment belongs to a boundary (internal or external) 
+it must be bound to a boundary condition object in order to supply 
+values for the flux computations. Hence there is no way of allowing 
+normal flow between neighbouring triangles in the case where they are 
+separated by an (unintended) internal boundary.
 An older version of pyvolution allowed None as a boundary object which 
 probably meant that a zero dirichlet condition was imposed. 
@@ -19 +24 @@
 Importance: High
 Suggested Action: Have pmesh ignore segments that aren't being tagged
- and that way they are only used to to define regions 
- (e.g. for variable resolution). 
+and that way they are exclusively used to to define regions 
+(e.g. for variable resolution).
 Status: Unresolved
+