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The Analysis has stopped because the Solver has exited unexpectedly

79 Views, 4 Replies
03/06/2018 10:07 AM

Hi, I’m new to CFD and trying to get a pneumatic actuator simulation to work (Motion with moving piston).


Every time I run it meshes then says ‘Meshing Complete’ and I get the error:


“The Analysis has stopped because the Solver has exited unexpectedly”


The way it’s supposed to work is 100psi comes in the inlet to the top of the piston, pushes it down and the air on the other side works its way down and back up to the outlet.


I have the inlet set to Pressure – 100psi – Steady State – Gage – Static

Outlet is set to Pressure – 0psi – Steady State – Gage – Static


The motion of the piston is Linear – Resistive Force 20N – Direction 0,1,0 – Initial Position 0 – Flow driven – Max Bound 0.5 – Min Bound -1


Mesh is autosize and I have tried refining it down to 0.7 and 0.5


Solve it set to Transient – Time Step 0.001 – Stop Time -1 – Inner iterations 1 – Save intervals 10 – Time steps to run 100 – Physics Flow checked, Incompressible


Things I’ve done to try and get it to work:

  • Edge Merge
  • Small Object remove
  • Adjusting the pressure in the Solve Solution Control options
  • Remove and unremoved the metal components of the part
  • Tested other models and they simulate fine

My computer specs are:

Windows 64 bit
Intel i7 8700k cpu
32Gb DDR4 4000mhz ram
SSD drive
GTX 1080 TI graphics



I’m guessing it is either something wrong with the model or a setting I have wrong, but the error message is so vague I have no idea where to start.


Any help would be greatly appreciated.



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Message 1 of 4 ( Views: 79 )

Re: The Analysis has stopped because the Solver has exited unexpectedly

03/07/2018 3:08 AM


There is no fluid material in your model. Did you forget to model the fluid material?



Xiaojin Zhang

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Message 2 of 4 ( Views: 64 )

Re: The Analysis has stopped because the Solver has exited unexpectedly

03/07/2018 5:58 AM

Thanks for the reply. I realised I uploaded the wrong file, I did have the fluid material allocated the file was from an earlier save. I think I found the issue was I selected incompressible instead of compressible in the solve and it seems to have worked.


However now the iterations have finished and it's up to this point:


*********** ANALYSIS STARTED ***********

Turbulent Compressible Flow is ON

Turbulence model: Standard k-epsilon

Intelligent Wall Formulation: OFF

Begin Post-Processing Calculations ...

Post-Processing Calculations Done

Begin Post-Processing File Output ...

Post-Processing File Output Done


and nothing more is happening since. Looking at task manager in windows it is showing one of the 'CFD Solver 2018' processes is still using up a core on the CPU and has been doing so for the last 5 hours when the iterations only took 2 hours to complete.


Is this compiling the results or has it crashed?

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Message 3 of 4 ( Views: 58 )

Re: The Analysis has stopped because the Solver has exited unexpectedly

03/07/2018 11:40 AM

My guess is that you have Anti Virus or a Firewall blocking the software, or you do not have the necessary read/write access to the folder.

Are you running on a local drive?(You do need to be).

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