Exporting Properties for Pele

The development of FuelLib was motivated by the need for more accurate liquid fuel property prediction in computational fluid dynamics (CFD) simulations. This section desscribes how to export properties from FuelLib for use in the spray module of the PelePhysics library[1] for combustion simulations in the PeleLMeX flow solver[2] [3].

Currently, there are two liquid property models implemented in Pele: the Group Contribution Method (GCM) and the original PeleMP (MP) model. The GCM is a replica of the model implemented in FuelLib and the MP model is the original model described in Owen et al. [1]

Each model has its own specific set of inputs required for Pele. The default parameters for the fl-export-pele command are set for the GCM. PelePhysics requires the following for each compound in the fuel for the GCM:

  • Hydrocarbon family

  • Molecular weight

  • Critical temperature

  • Critical pressure

  • Critical volume

  • Boiling point

  • Accentric factor

  • Molar volume

  • Mass specific heat coefficients

  • Latent heat of vaporization

The MP model in PelePhysics requires properties at a specified reference temperature for each compound in the fuel:

  • Critical temperature

  • Boiling point

  • Latent heat of vaporization

  • Specific heat

  • Density

  • Optionally, Antoine coefficients for vapor pressure

The fl-export-pele command generates an input file containing the necessary properties for each compound in the fuel. The following sections walk through the process and the available options for exporting properties from FuelLib to Pele.

Note

The units for PeleLMeX are MKS while the units for PeleC are CGS. This is the same for the spray inputs. Therefore, when running a spray simulation coupled with PeleC, the units for the liquid fuel properties must be in CGS. The default units for the fl-export-pele command is MKS, but users can specify CGS by using the -u cgs or --units cgs option.

Default Options

After installing FuelLib with pip install fuellib, run the following command in the terminal to export the required GCM parameters. The fuel here, “heptane-decane”, is a binary mixture of heptane and decane. Note that --fuel_name is the only required input:

fl-export-pele --fuel_name heptane-decane

Or using the short option -f:

fl-export-pele -f heptane-decane

This generates the following input file, FuelLib/exportData/sprayPropsGCM_heptane-decane.inp, for use in a PeleLMeX simulation:

# -----------------------------------------------------------------------------
# Liquid fuel properties for GCM in Pele
# Fuel: heptane-decane
# Number of compounds: 2
# Generated: <YYY-MM-DD> <HH-MM-SS>
# FuelLib remote URL: https://github.com/NatLabRockies/FuelLib.git
# Git commit: <commit-hash>
# Units: MKS
# -----------------------------------------------------------------------------

particles.fuel_species = NC7H16 NC10H22
particles.Y_0 = 0.7375 0.2625
particles.dep_fuel_species = NC7H16 NC10H22

# Properties for NC7H16 in MKS
particles.NC7H16_family = 0 # saturated hydrocarbons
particles.NC7H16_molar_weight = 0.100000 # kg/mol
particles.NC7H16_crit_temp = 549.855981 # K
particles.NC7H16_crit_press = 2821129.514417 # Pa
particles.NC7H16_crit_vol = 0.000425 # m^3/mol
particles.NC7H16_boil_temp = 379.073212 # K
particles.NC7H16_acentric_factor = 0.336945 # -
particles.NC7H16_molar_vol = 0.000146 # m^3/mol
particles.NC7H16_cp_a = 1636.255000 # J/kg/K
particles.NC7H16_cp_b = 3046.511000 # J/kg/K
particles.NC7H16_cp_c = -983.629000 # J/kg/K
particles.NC7H16_latent = 383110.000000 # J/kg

# Properties for NC10H22 in MKS
particles.NC10H22_family = 0 # saturated hydrocarbons
particles.NC10H22_molar_weight = 0.142000 # kg/mol
particles.NC10H22_crit_temp = 623.690516 # K
particles.NC10H22_crit_press = 2115522.932445 # Pa
particles.NC10H22_crit_vol = 0.000592 # m^3/mol
particles.NC10H22_boil_temp = 452.596977 # K
particles.NC10H22_acentric_factor = 0.468050 # -
particles.NC10H22_molar_vol = 0.000196 # m^3/mol
particles.NC10H22_cp_a = 1630.488028 # J/kg/K
particles.NC10H22_cp_b = 3098.105634 # J/kg/K
particles.NC10H22_cp_c = -1024.456338 # J/kg/K
particles.NC10H22_latent = 368035.211268 # J/kg

To include these parameters in your Pele simulation, copy the sprayPropsGCM_heptane-decane.inp file to the specific case directory and include the following line in your Pele input file:

FILE = sprayPropsGCM_heptane-decane.inp

Additional Options

There are many additional options that can be specified when running the fl-export-pele command:

  • -decomp, --fuel_decomp_name NAME: Name of the decomposition file (optional). If not provided, defaults to fuel name.

  • -dir, --fuel_data_dir PATH: Directory containing the fuel data files. Default: FuelLib/fuelData.

  • -u, --units {mks,cgs}: Units for the properties. Default: mks (use cgs for PeleC).

  • -dep, --dep_fuel_names NAME [NAME ...]: Gas-phase species that liquid fuel deposits to. Default: fuel compound names.

  • -pp, --use_pp_keys {true,false}: Use PelePhysics keys for each compound. Default: true.

  • -o, --export_dir PATH: Directory to export the file. Default: ./exportData.

  • -m, --export_mix {true,false}: Export fuel as a single mixture species. Default: false.

  • -mn, --export_mix_name NAME: Name of the mixture species if -m is set to true. Default: fuel name.

  • -l, --liq_prop_model {gcm,mp}: Liquid property model to use. Default: gcm.

  • -psat, --psat_antoine {true,false}: Use Antoine coefficients for vapor pressure in MP model. Default: true.

Liquid Species Deposit to Single Gas-Phase Species

To specify all liquid fuel species deposit to a single gas-phase species, run:

fl-export-pele -f heptane-decane -dep SINGLE_GAS

Or with long options:

fl-export-pele --fuel_name heptane-decane --dep_fuel_names SINGLE_GAS

Liquid Species Deposit to Specific Gas-Phase Species

Alternatively, users can specify a list of gas-phase species:

fl-export-pele -f heptane-decane -d GAS_1 GAS_2

which produces:

particles.fuel_species = NC7H16 NC10H22
particles.Y_0 = 0.7375 0.2625
particles.dep_fuel_names = GAS_1 GAS_2

# Properties for NC7H16 in MKS
...

Export Liquid Fuel as Single Mixture Species

To export mixture properties of a multicomponent fuel as a single component, run:

fl-export-pele -f heptane-decane -m true

Or with long options:

fl-export-pele --fuel_name heptane-decane --export_mix true

This generates the following input file, FuelLib/exportData/sprayPropsGCM_mixture_heptane-decane.inp:

# -----------------------------------------------------------------------------
# Liquid fuel properties for GCM in Pele
# Fuel: posf10264
# Number of compounds: 1
# Generated: <YYY-MM-DD> <HH-MM-SS>
# FuelLib remote URL: https://github.com/NatLabRockies/FuelLib.git
# Git commit: <commit-hash>
# Units: MKS
# -----------------------------------------------------------------------------

particles.fuel_species = LIQ-MIX
particles.Y_0 = 1.0
particles.dep_fuel_species = GAS

# Properties for LIQ-MIX in MKS
particles.LIQ-MIX_family = 0 # saturated hydrocarbons
particles.LIQ-MIX_molar_weight = 0.108418 # kg/mol
particles.LIQ-MIX_crit_temp = 564.653893 # K
particles.LIQ-MIX_crit_press = 2679711.894438 # Pa
particles.LIQ-MIX_crit_vol = 0.000458 # m^3/mol
particles.LIQ-MIX_boil_temp = 393.808839 # K
particles.LIQ-MIX_acentric_factor = 0.363221 # -
particles.LIQ-MIX_molar_vol = 0.000156 # m^3/mol
particles.LIQ-MIX_cp_a = 1635.099184 # J/kg/K
particles.LIQ-MIX_cp_b = 3056.851593 # J/kg/K
particles.LIQ-MIX_cp_c = -991.811612 # J/kg/K
particles.LIQ-MIX_latent = 380088.711936 # J/kg

This feature was used to generate the mixture properties for the conventional JP-8 jet fuel (posf10264), in the validation section of the PelePhysics documentation, where the liquid fuel is modeled as a single component that deposits to the HyChem gas-phase species for POSF10264.

Exporting Properties for the MP Model in Pele

Users can export properties for the MP model in Pele by specifying --liq_prop_model mp when running the export command:

fl-export-pele --fuel_name heptane-decane --liq_prop_model mp

This generates the following input file, FuelLib/exportData/sprayPropsMP_heptane-decane.inp, for use in a PeleLMeX simulation:

# -----------------------------------------------------------------------------
# Liquid fuel properties for MP in Pele
# Fuel: posf10264
# Number of compounds: 2
# Generated: <YYY-MM-DD> <HH-MM-SS>
# FuelLib remote URL: https://github.com/NatLabRockies/FuelLib.git
# Git commit: <commit-hash>
# Units: MKS
# -----------------------------------------------------------------------------

particles.fuel_species = NC7H16 NC10H22
particles.Y_0 = 0.7375 0.2625
particles.dep_fuel_species = NC7H16 NC10H22

# Properties for NC7H16 in MKS
particles.NC7H16_crit_temp = 549.855981 # K
particles.NC7H16_boil_temp = 379.073212 # K
particles.NC7H16_latent = 383110.000000 # J/kg
particles.NC7H16_cp = 1636.255000 # J/kg/K
particles.NC7H16_rho = 683.355277 # kg/m^3
particles.NC7H16_psat = 4.1644940008887215 1351.7047368174296 -51.094643469126446 100000.0 # Pa

# Properties for NC10H22 in MKS
particles.NC10H22_crit_temp = 623.690516 # K
particles.NC10H22_boil_temp = 452.596977 # K
particles.NC10H22_latent = 368035.211268 # J/kg
particles.NC10H22_cp = 1630.488028 # J/kg/K
particles.NC10H22_rho = 726.195341 # kg/m^3
particles.NC10H22_psat = 4.380101435197679 1702.1569216938776 -60.0774808903445 100000.0 # Pa

Users can choose to not use Antoine coefficients for vapor pressure in the MP model by specifying --psat_antoine False when running the export command:

fl-export-pele --fuel_name heptane-decane --liq_prop_model mp --psat_antoine False

This generates a similar input file as above, but without the Antoine coefficients for vapor pressure.