Floating point exception after some time of simulation

Shaik Raheem · July 31, 2023, 01:14

Hi all.
I am facing floating point exception error. I have tried so many ways to get rid of it. But still I am not able to resolve the issue.
I am doing a 2d simulation of the domain having porous media in which refrigerant is present. R134a refrigerant is given as real gas nist. Boundary conditions are as follows
bottom and left side walls as isothermal walls (at 308 K)
Right side is symmetry
top is considered as adiabatic wall.
Domain initial pressure is 11.5bar and temp is 351K . It has to cool to 308K
I am using udf to add mass and energy source terms.

error showing divergence detected in AMG solver. I couldn't sort out this error. I have set the verbosity in controls settings as 1. Then it was showing temp, pressure equations tolerance. There I have found that the temperature equation has high tolerance (1.643 e+3 we can see from the image attached). It was showing
"" Exit as omega becomes NaN for a norm of s equals to 0.0000e+00 "". I have no idea what it is and how to control it. I am attaching the error message here.

Please guide me to solve the issue.

Geetanjali · August 3, 2023, 07:15

were you able to solve it? I am also facing a floating point exception error. I am unable to solve it.

Shaik Raheem · August 3, 2023, 08:00

Quote:

Originally Posted by Geetanjali

were you able to solve it? I am also facing a floating point exception error. I am unable to solve it.

I have not yet resolved the issue. Waiting for some one to help. if your case is not the same, then you see the boundary conditions and also if you are having some code, care fully look at it. Some value might be going undefined.

MKuhn · August 4, 2023, 05:40

Hi Shaik,
only one hint. The Refprop Real Gas Model is only valid outside the saturation dome in FLUENT. Regarding your temperature and pressure, I'm not sure if you are in the two-phase region. This could be the reason for the floating point exception.

Shaik Raheem · August 4, 2023, 06:24

thank you for reply..

Actually it is single phase only. And i tried keeping ideal gas also. But same error is occurring.

MKuhn · August 4, 2023, 08:02

If you have mass terms in your UDF, the mass balance inside the UDF should be zero, as I can not see a flow boundary in your first post.

August 4, 2023, 08:02		#6
MKuhn Senior Member Moritz Kuhn Join Date: Apr 2010 Location: Germany, Dresden Posts: 207 Rep Power: 17	If you have mass terms in your UDF, the mass balance inside the UDF should be zero, as I can not see a flow boundary in your first post. Shaik Raheem likes this.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
icoFoam - Floating point exception (core dumped)	File	OpenFOAM Running, Solving & CFD	26	March 6, 2021 04:26
LES, Courant Number, Crash, Sudden	Alhasan	OpenFOAM Running, Solving & CFD	5	November 22, 2019 02:05
Facing a floating point error when reducing time step in a unsteady simulation	withwolf	STAR-CCM+	7	November 14, 2018 19:38
rhoSimpleFoam time step continuity errors	deepbandivadekar	OpenFOAM Running, Solving & CFD	2	September 13, 2018 05:50
Help with solving floating point exception crash.	rendagar	Main CFD Forum	1	March 26, 2014 07:34

August 3, 2023, 07:15		#2
Geetanjali New Member Geetanjali Alle Join Date: Aug 2023 Posts: 4 Rep Power: 2	were you able to solve it? I am also facing a floating point exception error. I am unable to solve it.

August 4, 2023, 05:40		#4
MKuhn Senior Member Moritz Kuhn Join Date: Apr 2010 Location: Germany, Dresden Posts: 207 Rep Power: 17	Hi Shaik, only one hint. The Refprop Real Gas Model is only valid outside the saturation dome in FLUENT. Regarding your temperature and pressure, I'm not sure if you are in the two-phase region. This could be the reason for the floating point exception.

August 4, 2023, 06:24		#5
Shaik Raheem New Member Shaik Raheem Join Date: Jul 2023 Posts: 10 Rep Power: 2	thank you for reply.. Actually it is single phase only. And i tried keeping ideal gas also. But same error is occurring.