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2D axisymmetric boundary condition
Posted Nov 23, 2010, 5:15 a.m. EST 4 Replies
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I am trying to model the groundflow around a pumping well. I am using 2D axisymmetric geometry. I have contracted a rectangle with the z axis passing through its centre. The pumping well is also a smaller rectangle that has the z axis passing through its centre.
I want to input for boundary condition a constant flow moving through the ground from left to right and as initial condition a pressure gradient from left to right (along the x-axis only if it was in cartesian coordinates). Can I do this in 2D axisymmetric geometry or do I have to use 3D?
thank you!
I want to input for boundary condition a constant flow moving through the ground from left to right and as initial condition a pressure gradient from left to right (along the x-axis only if it was in cartesian coordinates). Can I do this in 2D axisymmetric geometry or do I have to use 3D?
thank you!
4 Replies Last Post Nov 23, 2010, 9:47 a.m. EST
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Posted:
1 decade ago
Angeliki,
sounds like you can do it in 2D axial symmetry. Radial components of your fields must be zero on the symmetry axis, to avoid discontinuities. You should set up your geometry on one side of the symmetry axis. The corresponding 3D geometry results from a revolution around the z-axis.
Best regards
Edgar
sounds like you can do it in 2D axial symmetry. Radial components of your fields must be zero on the symmetry axis, to avoid discontinuities. You should set up your geometry on one side of the symmetry axis. The corresponding 3D geometry results from a revolution around the z-axis.
Best regards
Edgar
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Posted:
1 decade ago
thank you so much!
I changed my geometry to the one side of the axis. However my initial condition (before pumping water from the well) is not axisymmetric. It is steady flow in the ground from the left to the right (if we had 3D coordinates it would be constant flow in the x direction in the whole geometry and no flow in the y or z directions). Can I do this in 2-D axisymmetric? or do I need to contruct a 3D model?
thank you again!!
I changed my geometry to the one side of the axis. However my initial condition (before pumping water from the well) is not axisymmetric. It is steady flow in the ground from the left to the right (if we had 3D coordinates it would be constant flow in the x direction in the whole geometry and no flow in the y or z directions). Can I do this in 2-D axisymmetric? or do I need to contruct a 3D model?
thank you again!!
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Posted:
1 decade ago
Indeed, such a linear flow field is not axially symmetric and you will need to do it in 3D.
You might consider to start in 2D planar symmetry though. You could set up a T-shaped geometry with a horizontal flow field and something like a pipe entering in to the horizontal flow to model the well.
It is in general a good idea to start with something simplified in 2D, collect some results and then generalize into 3D.
Regards
Edgar
You might consider to start in 2D planar symmetry though. You could set up a T-shaped geometry with a horizontal flow field and something like a pipe entering in to the horizontal flow to model the well.
It is in general a good idea to start with something simplified in 2D, collect some results and then generalize into 3D.
Regards
Edgar
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Posted:
1 decade ago
Hi
if I remember right in 2D axi you should stay on the right side (Q1+Q4) of the axis, and if possible avoid going onto the axis (not strictly required, but in V3.5 you could only have brick elements on the axis), in V4 I'm not sure anylonger how it is, apart that the +X rule holds too
--
Good luck
Ivar
if I remember right in 2D axi you should stay on the right side (Q1+Q4) of the axis, and if possible avoid going onto the axis (not strictly required, but in V3.5 you could only have brick elements on the axis), in V4 I'm not sure anylonger how it is, apart that the +X rule holds too
--
Good luck
Ivar