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A Mesh or Solver setup problem

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Old   November 5, 2006, 13:20
Default Hello, I was trying to sim
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Philippose Rajan
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Hello,
I was trying to simulate a couple of flow cases through hydraulic valves. My first tests worked out fine (simulations to within 1.5 to 2 l/min of measurements), and then I started doing further simulations with smaller systems, and with valves in situations where the spool is only around 0.2 to 0.4mm open.

In these cases, I started seeing an effect, where, just downstream from the regions with the highest velocity, there is a sudden discontinuity in the velocity field, in which the velocity drops to zero, and further downstream the flow shows up again.

I initially thought my mesh was too coarse, and I tried with another mesh of roughly double the number of cells, and higher mesh grading, but the results were more or less the same.

I took a couple of screen shots from Paraview, and shall try to attach one of them here (havent been successful before!). In case I am unable to attach it here, is there another option?



Does anyone have any suggestions as to what the problem might be?

Thanks, and have a nice week ahead!

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Old   November 5, 2006, 13:28
Default http://www.cfd-online.com/Open
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Old   November 5, 2006, 14:46
Default Ok... Trying now from firefox
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Ok... Trying now from firefox 2.0 in Windows :-) I hope it works this time! If not, I have only one more option... to try Internet Explorer...!



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Old   November 5, 2006, 14:54
Default My last try... from Internet E
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My last try... from Internet Explorer.... I apologise again for flooding the group...



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