folded mesh

alinik · January 19, 2011, 01:28

Hi everyone

I get this error when I solve a simple FSI problem. though the structural material is pretty weak but because others have solved the exact problem before, thus this error is unlikely to be result of structural model and material.

+--------------------------------------------------------------------+ | ERROR #002100011 has occurred in subroutine cVolSec. |
| Message: |
| A negative SECTOR volume has been detected. Execution will proceed |
| but this is a possible cause of robustness problems. |
| The location of the first negative volume is reported below. |
| Volume : -0.3764E-13 |
| Location : ( 0.35425E-01, -0.13897E-01, -0.18320E-02) |
| This warning may be made fatal by setting the expert parameter |
| 'negative volume option = 1'. |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| CFX encountered the error: |
| 0. A folded mesh has oc- |
| curred. This process will shut down as soon as possible. |
| |
| |
| |
+--------------------------------------------------------------------+
I always get this error when the solution reaches the time 0.081, no matter how small time step or what mesh I use.
besides I ramp up the BCs. what else could be the problem?

ghorrocks · January 19, 2011, 04:51

This means an element has turned inside out due to excessive mesh motion. Things to look at, in the approximate order you should do them in:
1) Check the motion is correct
2) try adjusting the mesh smoothing
3) modify the geometry by making the region around the body a fixed mesh relative to the body and the distorting grid further away from the body
4) Use a GGI with either linear or rotating motion as they can handle more deflection
5) Use a remeshing step to improve mesh quality.

January 19, 2011, 01:28	folded mesh	#1
alinik Senior Member ali Join Date: Oct 2009 Posts: 318 Rep Power: 17	Hi everyone I get this error when I solve a simple FSI problem. though the structural material is pretty weak but because others have solved the exact problem before, thus this error is unlikely to be result of structural model and material. +--------------------------------------------------------------------+ \| ERROR #002100011 has occurred in subroutine cVolSec. \| \| Message: \| \| A negative SECTOR volume has been detected. Execution will proceed \| \| but this is a possible cause of robustness problems. \| \| The location of the first negative volume is reported below. \| \| Volume : -0.3764E-13 \| \| Location : ( 0.35425E-01, -0.13897E-01, -0.18320E-02) \| \| This warning may be made fatal by setting the expert parameter \| \| 'negative volume option = 1'. \| +--------------------------------------------------------------------+ +--------------------------------------------------------------------+ \| ERROR #001100279 has occurred in subroutine ErrAction. \| \| Message: \| \| CFX encountered the error: \| \| 0. A folded mesh has oc- \| \| curred. This process will shut down as soon as possible. \| \| \| \| \| \| \| +--------------------------------------------------------------------+ I always get this error when the solution reaches the time 0.081, no matter how small time step or what mesh I use. besides I ramp up the BCs. what else could be the problem?

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January 19, 2011, 04:51		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	This means an element has turned inside out due to excessive mesh motion. Things to look at, in the approximate order you should do them in: 1) Check the motion is correct 2) try adjusting the mesh smoothing 3) modify the geometry by making the region around the body a fixed mesh relative to the body and the distorting grid further away from the body 4) Use a GGI with either linear or rotating motion as they can handle more deflection 5) Use a remeshing step to improve mesh quality.