Learning Forum

[Stephen Orritt]

Hi all,

I am getting an error when running a transient simulation which is as follows: 

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

The simulation is modelling a wind turbine using a momentum source, the simulations run well and seem to agree with literature data when run as a steady-state frozen rotor simulation (image below). However, when switching over to a transient simulation I get the error stated at the first timestep. Can momentum sinks be used for rotating transient simulations? I have looked at the documentation which does not point to anything obvious other than rechecking the physics and mesh. I believe the mesh is of suitable detail and quality for this initial simulation. I have also looked at changing the timestep down to E-5 seconds and that does not solve the issue. One thing I have noticed in the output file is the wallscale residual seems to fail initially, could this be the issue and how could I solve this? 

 SOLVING : Wall Scale                                               |
 ----------------------------------------------------------------------
 |       Equation       | Rate | RMS Res | Max Res |  Linear Solution |
 +----------------------+------+---------+---------+------------------+
 | Wallscale            | 0.00 | 2.4E-05 | 1.2E-03 |  9.6  2.8E+01  F |
 +----------------------+------+---------+---------+------------------+
 | Wallscale            |99.99 | 6.8E+13 | 1.2E+15 |  9.6  8.3E-02  OK|
 +----------------------+------+---------+---------+------------------

Many thanks

[B D]

Hi Stephen,

Generally this error is received when the boundary conditions are set incorrectly or if the initial values are inappropriate.

Since you are running a transient case, please make sure the interface definition are correct and the initial values you are using for simulation are reasonable.