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Local User Groups / Local User Group Mid-Atlantic USA

2010-09-08T17:03:19Z

← Older revision		Revision as of 17:03, 2010 September 8
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	<noinclude>		<noinclude>
		+	== ANNOUNCEMENT of Mid-Atlantic OpenFOAM Users Group at Penn State ==
		+	[[Category:FeaturedArticle]]
		+
		+	Dear Foamers in the Mid-Atlantic/Midwest USA (PA/NY/MD/VA/WV/OH/NJ/DE/...)
		+
		+	The second Users Group Meeting (Stammtisch) for the Mid-Atlantic/Midwest region of the US will be held at the University of Michigan on Saturday, October 23, 2010.
		+
		+	Following the great success of the first meeting, the format will be very similar with technical presentations in the morning and birds-of-a-feather sessions in the afternoon.
		+
		+	Please send an email to Kevin Maki (kjmaki@umich.edu) if you are interested in attending. Also, please let me know if you have any suggestions to make the meeting work best for the community. In addition, I am posting this announcement to the forum and the extend-project portal. I will suggest that the portal be used for public comments and interaction:
		+
		+	1. Forum: http://www.cfd-online.com/Forums/openfoam-news-announcements-other/70236-mid-atlantic-usa-openfoam-users-group-penn-state.html#post274455
		+
		+	2. Portal: http://www.extend-project.de/user-gr...d-atlantic-usa
		+
		+	Kevin Maki
		+
	== ANNOUNCEMENT of Mid-Atlantic OpenFOAM Users Group at Penn State ==		== ANNOUNCEMENT of Mid-Atlantic OpenFOAM Users Group at Penn State ==

User:Kjmaki

2010-09-08T14:18:00Z

New user account

Contrib snapEdgeDescription

2010-09-07T18:25:25Z

New page

The idea behind snapEdge is pretty straightforward and I will try to describe it below.
The implementation however was not straightforward (as I thought it would be), but below is a description of how I want it to work.

The first step is to extract the features from the STL.

An STL is just a collection of triangles and every edge thus has 2 triangles associated to it.

If it doesnt, it is a an edge and will be added to the feature lines.

Otherwise the dot product of the face normals is calculated (and normalized)

If it is equal to 1 it means that the two planes are parallel and if it is equal to 0 the planes are perpendicular.

The feaureAngle then decides which edges should be included in the features used for the snapping.

The next step is to perform the same operation on the patches. (This step requires special care for parallel processing as it may extract false edges on the processor boundaries, which has not yet been included)

We now have a set of (mesh) edges that we want to attach (or snap) to the feature lines.

The third step is to loop over all the features and for each edge we calculate the
distance for both points to that feature. If the distance to the feature is smaller than the tolerance * | edge length | we associate that edge
to that feature line. It also needs to have the closest point inside the 2 points on the feature line. Note that the 2 points on the edge does
not have to belong to the same feature.

If the edge already is associated with another feature line we check which one is best suited among the two features.
This is based on angle and distance to the feature line. An edge may be close to the feature but is disregarded if the angle is too large.

After this step the 2 points on every edge have a final destination point on the associated feature line.
This is the position to which the point want to move.

The fourth step is to check for overlaps. Two edges may be mapped in such a way that they occupy the same segment on the feature line.
Thus every final destination point for each edge is mapped to other final destination points edges.
If they overlap we need to decide which one we want to actually move, the other edge will be ignored..
This is also based on angle and proximity. Although a point may be close it shouldn't be mapped if the edge is not parallell enough.
This is set by the parallellAngle criteria. If the edge angles are below this, the closest point will be chosen, ottherwise the angle will decide.

We now have all the info we need to move the points and the last step is to actually move the points.
However, we do not move them to the edge in 1 go, since I have found that it is more stable to use underrelaxation as this
will capture corners better.

There is also a reason why we associated edges to features and not points as this will allow a point to be associated with multiple features
and corners can be captured better.

--[[User:Niklas|Niklas]] 20:13, 7 September 2010 (CEST)

Contrib snapEdge

2010-09-07T16:48:40Z

← Older revision		Revision as of 16:48, 2010 September 7
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	Download from here http://openfoam.nequam.se/cases/snapEdge.tgz (update: 1 sept 2010).		Download from here http://openfoam.nequam.se/cases/snapEdge.tgz (update: 1 sept 2010).
		+
		+	[[ Contrib_snapEdgeDescription \| How does it work? ]]

	To install it, unpack it anywhere with 'tar zxfv snapEdge.tgz'. Go to the snapEdge directory and run wmake.		To install it, unpack it anywhere with 'tar zxfv snapEdge.tgz'. Go to the snapEdge directory and run wmake.

Tip Cross Compiling OpenFOAM 1.7 in Linux For Windows with MinGW

2010-09-07T14:37:24Z

History:

← Older revision		Revision as of 14:37, 2010 September 7
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	= History =		= History =
		+	[[User:Wyldckat\|Wyldckat]] 16:37, 7 September 2010 (CEST) - Patches for 1.7.0 have been updated. There were a couple of glitches that needed fixing for a proper clean build. These were tested with OpenSUSE 11.1 x64 and custom mingw-w64.
		+
	[[User:Wyldckat\|Wyldckat]] 20:10, 6 September 2010 (CEST) - Added information and step for running '''fixPatchExeNames'''.		[[User:Wyldckat\|Wyldckat]] 20:10, 6 September 2010 (CEST) - Added information and step for running '''fixPatchExeNames'''.

File:PatchesNBatches170.tar.gz

2010-09-07T14:34:59Z

uploaded a new version of "[[File:PatchesNBatches170.tar.gz]]" Second version for 1.7.0 uploaded into the wiki. This version is tightly coupled with blueCFD 1.7-1 patch version 1.

User:Liucenfan288

2010-09-07T03:26:12Z

New user account

Tip Cross Compiling OpenFOAM 1.7 in Linux For Windows with MinGW

2010-09-06T18:10:36Z

History:

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