[manupanand]

I am facing an error, I am simulating a compressor CFD simulation, working fluid air.

The error is following.
Why is it happening?

Is it because of my boundary conditions

"The maximum Mach number is 3.709E+01. " why this is showing?
************************************************** ************* ================================================== ====================
OUTER LOOP ITERATION = 293 ( 40) CPU SECONDS = 3.792E+05 (6.057E+04)
----------------------------------------------------------------------
| Equation | Rate | RMS Res | Max Res | Linear Solution |
+----------------------+------+---------+---------+------------------+
| U-Mom | 0.32 | 1.8E-04 | 1.0E-01 | 1.7E-03 OK|
| V-Mom | 0.37 | 1.4E-04 | 1.1E-01 | 1.4E-03 OK|
| W-Mom | 0.57 | 6.1E-04 | 8.4E-01 | 2.9E-03 OK|
| P-Mass | 0.38 | 2.3E-04 | 4.6E-01 | 5.2 3.6E-02 OK|
+--------------------------------------------------------------------+
| ****** Notice ****** |
| A wall has been placed at portion(s) of an OUTLET |
| boundary condition (at 53.5% of the faces, 46.1% of the area) |
| to prevent fluid from flowing into the domain. |
| The boundary condition name is: stator Outlet. |
| The fluid name is: Fluid 1. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead. |
+--------------------------------------------------------------------+
+----------------------+------+---------+---------+------------------+
| H-Energy | 2.10 | 1.1E-03 | 1.3E+00 | 5.7 4.9E-04 OK|
+----------------------+------+---------+---------+------------------+
| K-TurbKE | 0.10 | 5.2E-04 | 9.6E-01 | 5.7 4.1E-04 OK|
| E-Diss.K | 0.44 | 9.5E-04 | 1.8E+00 | 23.8 4.8E-08 OK|
+----------------------+------+---------+---------+------------------+
+--------------------------------------------------------------------+
| Notice: The maximum Mach number is 3.709E+01. |
+--------------------------------------------------------------------+

================================================== ====================
OUTER LOOP ITERATION = 294 ( 41) CPU SECONDS = 3.806E+05 (6.201E+04)
----------------------------------------------------------------------
| Equation | Rate | RMS Res | Max Res | Linear Solution |
+----------------------+------+---------+---------+------------------+

+--------------------------------------------------------------------+
| ERROR #004100018 has occurred in subroutine FINMES. |
| Message: |
| Fatal overflow in linear solver. |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| An error has occurred in cfx5solve: |
| |
| The ANSYS CFX solver exited with return code 1. No results file |
| has been created. |
+--------------------------------------------------------------------+

End of solution stage.

+--------------------------------------------------------------------+
| The following user files have been saved in the directory |
| D:/manupa/CFX/workdirectory/1500_retrofit/retro_pending/dp0_CFX_S- |
| olution/CFX_006: |
| |
| mon, pids |
+--------------------------------------------------------------------+


+--------------------------------------------------------------------+
| For CFX runs launched from Workbench, the final locations of |
| directories and files generated may differ from those shown. |
+--------------------------------------------------------------------+


+--------------------------------------------------------------------+
| Warning! |
| |
| After waiting for 60 seconds, 1 solver manager process(es) appear |
| not to have noticed that this run has ended. You may get errors |
| removing some files if they are still open in the solver manager. |
+--------------------------------------------------------------------+


This run of the ANSYS CFX Solver has finished.

[neelcfd]

This seems to be associated with density of air & absolute pressure. Please share Boundary conditions details & Models beings used or the .out file.

[ghorrocks]

Your simulation has diverged and the crazy Mach number in the iteration before it diverges is because it is starting to go haywire.

See FAQ: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

[manupanand]

I have attached the out file as logfile.txt

[ghorrocks]

There is nothing obviously wrong with the output file, but that only shows part of what is happening. Have you read the FAQ I linked to? It says exactly what you need to look for.

[zacko]

Are your boundary conditions correct ?
Is it correct, that your Inlet Total pressure is set dependent on the outlet total pressure of your diffuser?

[Opaque]

Zacko's comment is spot ON.

For a device that requires work (rotor does), and includes friction (viscous fluid), how can the Total Pressure can be conserved from Inlet to Outlet

Total pressure Outlet = Total Pressure Inlet + <Total Pressure Increase due to work> - Total Pressure Losses (Rotor + Stator)

Something seems wrong.