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How to measure the position of the free surface?

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Old   November 16, 2009, 10:28
Default How to measure the position of the free surface?
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Hernán
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Hello, good afternoon.

We are simulating several laboratory tests with Star CCM+ (tests carried out in a wave tank), in order to compare the results of the physical model with numerical model, we must to take measurements of free surface position (free surface elevation in z axis) along different points.

How is the manner to record this data (a probe, a point), creating another derived part?

I hope this information is enough, if you need more details, please contact me.

Thank´s for your attention.

Best regards.
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Old   November 24, 2009, 16:25
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Aroon
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You can create a Point Probe or a Plane Probe as is necessary and generate a report to check your results
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Old   November 25, 2009, 01:24
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NB: a point or line probe is not the answer in this case. Here is what to do:
1. Create an iso-surface at VOF=0.5
2. Create a vertical plane section at the x location but with the iso-surface as the input part. The resulting section is then a line at the intersection of the isos and the plane
3. Create another vertical plane section at the required y location and use the above line section as the part.
Now that section is actually a point at the intersection of those three parts - since one of them is the water height it will move up and down during solution.
4. Create a Max report with field function Position[2] - ie z and the point section as the part.
5. Create a monitor and plot of this report - DONE.
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Old   November 25, 2009, 04:44
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Hello, good morning from Spain,

Thank´s for your prompt reply.

We have found another proccedure for measuring the position of free surface, is the following method:

1.- Create a vertical plane section normal to wave advancing direction.
2.- Create a report to measure the Area Averaged at this section.
3.- Set at this report Volume Fraction of Water as Scalar field function.
4.- Create a monitor and a plot from this report.
5.- The values you will obtain are the percentage of water you have at this section, in another words, the water level time series at this point.


Best regards.
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Old   November 26, 2009, 03:36
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Yes this is also a good method which I use when I require the hgt averaged across a plane (and if you want it in just say a 1m wide plane then define a constrained plane).
However you requested the level at 'points' rather than planes so this is the method I suggested - eg to track the bow wave development from a boat hull - very three dimensional.
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Old   March 17, 2010, 23:04
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how can i create a surface elevation plot for the free surface?
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