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-   -   newtons method failed/fatal overflow (https://www.cfd-online.com/Forums/cfx/21035-newtons-method-failed-fatal-overflow.html)

ioana March 2, 2005 03:57

newtons method failed/fatal overflow
 
Dear CFX users,

I am simulating a fire 10*10*10 m (180MW)on a offshore platform. I have done a coarse mesh of 250.000 cells (the domain is big around 100^3 m^3) and the simulation runs without error. At the same case using a finer mesh (650.000 cells) i have received the following notice:

****** Notice ****** | | Newtons method failed to converge in 100 iterations. This | | occured while computing the following variable: | | | | Variable Name : Temperature | | Location Name : FluidZone | | Mesh location : VERTICES | | Mesh entity : | | Last 3 Changes : 4.59189E+01 4.59189E+01 4.59189E+01 | | Tolerance : 1.0000E-02 | | | | The Newton iteration was either slowly converging or has stalled. | | The solver will continue with the variable set as it was on the | | final iteration. If this situation continues you might try | | increasing the number of iterations allowed for Newtons method. | | This can be changed by setting one of the parameters: | | | | Temperature : "Constitutive Relation Iteration Limit" | | Pressure : "Newton Pressure Iteration Limit" | | | | for your mixture using the definition file editor. | +----------------------------------------------------

After several iteration the solver stops with the error:

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

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The CFX-5 solver exited with return code 1. No results file has | | been created. | +--------------------------------------------------------------------+

Any ideas? Thanks in advance,

Ioana


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