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Strange error when increasing grid resolution

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Old   February 18, 2009, 09:05
Default Hi, I have a 2D uniform mes
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Andreas Feymark
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I have a 2D uniform mesh with 0.5<=x<=1, 0<=y<=0.5, created using blockMesh. I'm computing the following expression,

where x() and y() is defined in the following way,

tmp<volscalarfield> MSolution::x() const
return mesh_.C().component(vector::X)/L_;
where L_=1.0m.
For a small grid, 20x20 nodes large, this gives PMS=0.0 at the boundaryFields, (x=0.5, 0<=y<=0.5) and (y=0.5, 0.5<=x<=1). This is the correct behavior. The problem is when I increase the grid resolution to maybe 100x100. Then I get values that are not equal to 0 on the boundary. I think it's important to add that these values are of the magnitude 1e-18, quite small depending on the circumstances. I have checked the polyMesh directory and everything seems to be correct there. I really don't understand this. Any suggestions?

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