Exporting GCM-Based Mixture Properties for Converge
The export script, Export4Converge.py
, generates a csv file named mixturePropsGCM_<fuel_name>.csv
containing
mixture property predictions for a given fuel over a specified temperature range. The properties include:
Critical temperature
Dynamic viscosity
Surface tension
Latent heat of vaporization
Vapor pressure
Density
Specific heat
Thermal conductivity
Warning
Mixture properties for critical temperature, latent heat, and specific heat are provided by Conventional mixing rules and need additional validation.
This example walks through the process and the available options for exporting GCM-based mixture properties for
“posf10325”, which is conventional Jet-A, using the Export4Converge.py
script.
Default Options
From the FuelLib
directory, run the following command in the terminal, noting that --fuel_name
is the only required input:
cd FuelLib/source
python Export4Converge.py --fuel_name posf10325
This generates the file FuelLib/exportData/mixturePropsGCM_posf10325.csv
with mixture
property predictions from 0 K to 1000 K for use in a Converge simulation.
Additional Options
There are several additional options that can be specified when running the export script:
--units
: Specify the units for the mixture properties. The default is “mks” but users can set the units to “cgs”.--temp_min
: Specify the minimum temperature. The default is 0 K.--temp_max
: Specify the maximum temperature. The default is 1000 K.--temp_step
: Specify the temperature step size. The default is \(\Delta T = 10\) K.--export_dir
: Specify the directory to export the file. The default is “FuelLib/exportData”.--fuel_data_dir
: Specify the directory containing the fuel data files. The default is “FuelLib/fuelData”.
Note
The mixture property predictions may not be valid from the specified temp_min
to temp_max
,
as the mixture properties are based on the GCM properties and correlations of the individual
components. Constant values are set for temperatures below the freezing point of the mixture or above
the minimum critical temperature of all compounds in the fuel. These temperature values will be noted in the
terminal output and should be considered when using the mixture properties in a simulation.