Learning Forum

[abbas]

Hello every one,

 

I generated an RGP table and during the process, I received the following warning.

How or where can I change the Newton iteration underrelaxation factor. 

 | Temperature : "Constitutive Relation Under Relaxation"             |

 | Pressure    : "Newton Pressure Under Relaxation"

 

Best regards

Abbas

[Amine Ben Hadj Ali]

Does the situation persist?

[abbas]

Hi,

 

Yes, the situation persists. Therefore I am looking to reduce the relaxation factor.

Could you please let me know, how can I do that?

 

Thanks

[Amine Ben Hadj Ali]

 Copy paste here the CCL of your binary mixture (right click on it and edit in command editor then copy).

[abbas]

 

LIBRARY:

&replace MATERIAL: CO2

Binary Material1 = CO2V

Binary Material2 = CO2L

Material Description = Carbon Dioxide CO2

Material Group = User

Object Origin = User

Option = Homogeneous Binary Mixture

SATURATION PROPERTIES:

Component Name = CO2L

Option = Table

Table Format = TASCflow RGP

Table Name = Dcfx/CO2-high.rgp

END

END

END

 

 

[Amine Ben Hadj Ali]

Add following lines under the line containing Option =Homogeneous Binary Mixture:

 Newton Pressure Criterion = 1[Pa] (Default)

 Newton Pressure Iteration Limit = 150 (Default)

 Newton Pressure Under Relaxation = your value (1 is  Default)

 

This would add the under-relaxation of NR-P. If you do not understand what is the meaning of Newton Raphson and why is it required then check some references. In general, one has to ensure that every single line in the setup is correct before starting under relaxation this numerical scheme.

 

I hope this helps. I leave feedback questions for other community members.