[Fat shady]

Hello everyone,
I want to use CFX to simulate the case of non-equilibrium phase transition of turbine expander (water vapor of IAPWS IF97 can be successfully simulated), but I use the RGP file of methane as a fluid to import into CFX, and the solution will report errors.
(When the fluid changes from water vapor to methane, the surface tension coefficient must be added,The reason for the error is precisely the surface tension coefficient：“SIGMA”)

The boundary conditions are Pin=12MPa,Tin=299.15K,Pout=6.7MPa.

Error reported as follows:
+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| NAME_MOD: Error finding variable "SIGMA" within domain "R1". CCL |
| is possibly invalid. |
+--------------------------------------------------------------------+

I have tried many modifications but can not solve this problem, please help me！
Thank you very much!

[Opaque]

Originally Posted by Fat shady

Hello everyone,
I want to use CFX to simulate the case of non-equilibrium phase transition of turbine expander (water vapor of IAPWS IF97 can be successfully simulated), but I use the RGP file of methane as a fluid to import into CFX, and the solution will report errors.
(When the fluid changes from water vapor to methane, the surface tension coefficient must be added,The reason for the error is precisely the surface tension coefficient：“SIGMA”)

The boundary conditions are Pin=12MPa,Tin=299.15K,Pout=6.7MPa.

Error reported as follows:
+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| NAME_MOD: Error finding variable "SIGMA" within domain "R1". CCL |
| is possibly invalid. |
+--------------------------------------------------------------------+

I have tried many modifications but can not solve this problem, please help me！
Thank you very much!

Do you have an RGP file describing the Methane-Vapor and Methane Liquid thermodynamics?
Did you setup the case using a homogeneous binary mixture? Methane-Vapor and Methane-Liquid

[Fat shady]

Originally Posted by Opaque

Do you have an RGP file describing the Methane-Vapor and Methane Liquid thermodynamics?
Did you setup the case using a homogeneous binary mixture? Methane-Vapor and Methane-Liquid

Some thermodynamic parameters of the methane RGP file are as follows：

PMIN_SUPERHEAT
2.5000000E+004
PMAX_SUPERHEAT
6.5000000E+007
TMIN_SUPERHEAT
1.5000000E+002
TMAX_SUPERHEAT
5.0000000E+002
TMIN_SATURATION
1.5000000E+002
TMAX_SATURATION
2.2000000E+002
SUPERCOOLING
0.0000000E+000
P_CRITICAL
4.5992000E+006
P_TRIPLE
1.1696000E+004
T_CRITICAL
1.9056400E+002
T_TRIPLE
9.0694100E+001
GAS_CONSTANT
5.1827050E+002

I used the RGP plugin to generate methane.rgp file for methane vapor and methane liquid, vapor and liquid are selected thermodynamic states "liquid" and "gas" inside the CFX-Pre materials. Homogeneous binary mixture are defined in terms of methane vapor and methane liquid. The initial condition is that the methane gas phase volume fraction is 1 and the methane liquid phase volume fraction is 0. The aim is to consider droplet formation during expansion.

[Opaque]

If you think every other detail of your setup is correct, I would replace the methane RGP files with the provided RGP for water/steam.

there should be no difference since the materials' properties are just numbers. If the use persists, you are missing something in the setup.

[Fat shady]

Originally Posted by Opaque

If you think every other detail of your setup is correct, I would replace the methane RGP files with the provided RGP for water/steam.

there should be no difference since the materials' properties are just numbers. If the use persists, you are missing something in the setup.

Dear Opaque,
If you wish, please provide a water/steam RGP file. I would appreciate it very much. I also check my Settings for any omissions or problems.Thanks a lot.

[Opaque]

Originally Posted by Fat shady

Dear Opaque,
If you wish, please provide a water/steam RGP file. I would appreciate it very much. I also check my Settings for any omissions or problems.Thanks a lot.

They are part of the installation.

[zhanghuicheng@nnu.edu.cn]

Originally Posted by Fat shady

Hello everyone,
I want to use CFX to simulate the case of non-equilibrium phase transition of turbine expander (water vapor of IAPWS IF97 can be successfully simulated), but I use the RGP file of methane as a fluid to import into CFX, and the solution will report errors.
(When the fluid changes from water vapor to methane, the surface tension coefficient must be added,The reason for the error is precisely the surface tension coefficient：“SIGMA”)

The boundary conditions are Pin=12MPa,Tin=299.15K,Pout=6.7MPa.

Error reported as follows:
+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| NAME_MOD: Error finding variable "SIGMA" within domain "R1". CCL |
| is possibly invalid. |
+--------------------------------------------------------------------+

I have tried many modifications but can not solve this problem, please help me！
Thank you very much!

Hello Sir. It's my honor to find our research aligning-I'm also working on non-equilibrium condensation ,I am currently implementing the IAPWS-IF97 steam3vl formulation from the standard material library, with classical homogeneous nucleation and droplet growth mechanisms activated post-condensation. However, certain thermodynamic variables in the simulation results exhibit unresolved discrepancies. Would you be available for a technical discussion regarding this implementation challenge? Thank you very much!

[Fat shady]

Originally Posted by zhanghuicheng@nnu.edu.cn

Hello Sir. It's my honor to find our research aligning-I'm also working on non-equilibrium condensation ,I am currently implementing the IAPWS-IF97 steam3vl formulation from the standard material library, with classical homogeneous nucleation and droplet growth mechanisms activated post-condensation. However, certain thermodynamic variables in the simulation results exhibit unresolved discrepancies. Would you be available for a technical discussion regarding this implementation challenge? Thank you very much!

Hello, based on your description, the simulation of wet steam unbalanced condensation can refer to the simulation cases in the CFX help documentation.The website address is：
https://ansyshelp.ansys.com/public/a.../ljjhk225.html

If you have any other questions, you can also discuss them together. Currently, the simulation can be successfully carried out based on the case, but when it comes to applying to our own boundary conditions, some errors will occur.

Thank you!

[zhanghuicheng@nnu.edu.cn]

Originally Posted by Fat shady

Hello, based on your description, the simulation of wet steam unbalanced condensation can refer to the simulation cases in the CFX help documentation.The website address is：
https://ansyshelp.ansys.com/public/a.../ljjhk225.html

If you have any other questions, you can also discuss them together. Currently, the simulation can be successfully carried out based on the case, but when it comes to applying to our own boundary conditions, some errors will occur.

Thank you!

Thank you very much for sharing this learning material, but I cannot open the provided link. Would there be an alternative link or access method available?

[ghorrocks]

If you have a valid ANSYS support license the link should work. The information on the link is copyright to ANSYS so we cannot copy it to somewhere else.