Learning Forum

[rahul159753159]

Hello,

I have created a predefined mixture of fluid in refprop (Version 10.0) to be used in fluent (Version 2025R2). I have the mass fractions and all the .fld files that refprop is using to create the predefined mixture. I don't really know how to create RGP for that. I looked out for this thread How to generate and setup RGP-Tables for CFX multiphase flow simulations but the zip file seems tp be removed/missing. Can anyone help me with this please?

 

Thanks

[SRP]

Hi,

You can check user's manual for creating RGP file: 6.1. Real Gas Property (RGP) Table Files

[jcooper]

Hi Rahul:

The generic process for creating RGP files uses the ANSYS System coupling application. You supply a Python file with instructions for the mixture and then run from the command line:

"C:\Program Files\ANSYS Inc\v251\SystemCoupling\bin\systemcoupling" -R script.py

The resulting RGP file can be used with either CFX or Fluent.

Below is a sample script for a mixture:

 

import os
import pyExt.RefProp as arp

fluidsPath = arp.getFluidsPath()
mat = arp.RefPropLib()
#
# Enter mixture components - these all must exist in the material database
#

fluidList = arp.FluidList()
fluidList.append("R23.FLD")
fluidList.append("R116.FLD")
#
# Enter mass ratios of mixture components
#
composition = arp.Values()
composition.append(0.46)
composition.append(0.54)

matInfo = mat.setmix(fluidsPath, fluidList, composition)
mixInfo = mat.info()
print(
    f"Critical point       : (",
    mixInfo.tempCrit,
    ", ",
    mixInfo.presCrit,
    ", ",
    mixInfo.rhoCrit,
    ")",
)
print(
    f"Cricondenbar point   : (",
    mixInfo.psatMaxT,
    ", ",
    mixInfo.psatMax,
    ", ",
    mixInfo.psatMaxD,
    ")",
)
print(
    f"Cricondentherm point : (",
    mixInfo.tsatMax,
    ", ",
    mixInfo.tsatMaxP,
    ", ",
    mixInfo.tsatMaxD,
    ")",
)
#Set the variable interpError as follows to define an accuracy, may need to adjust
# for convergence 
# 
#'low' :       1e-3  
#'medium':     1e-4 
#'med-high' :  5e-5   
#'high' :      2e-5 
#'very-high' : 1e-5
#
interpError = 5.0e-5

#
#Set table ranges larger than problem range to allow for overshoots
#

Tmin = 200.0
Tmax = 500.0
Pmin = 3000
Pmax = 2.4e06

#
# generate tables - pass arp.ADAPT_AUTO_TP for 1D tables and arp.ADAPT_AUTO_2D for 2D
#

R508BL = arp.RGPLiquid("R508BL", Tmin, Tmax, Pmin, Pmax, interpError, arp.ADAPT_AUTO_TP)
liquid_tab = arp.buildRGPComponent(R508BL)
arp.writeRGPfile("R508BL.rgp", liquid_tab)

R508BV = arp.RGPVapor("R508BV", Tmin, Tmax, Pmin, Pmax, interpError, arp.ADAPT_AUTO_TP)
vapor_tab = arp.buildRGPComponent(R508BV)
arp.writeRGPfile("R508BV.rgp", vapor_tab)

mat.release()