ABSTRACT
Currently, all commercial software for engine modeling investigates the dispersed droplet phase of the injection process. Understanding the effect of geometry of the injector nozzle, initial jet conditions, fluid properties in the liquid film, breakup, resulting droplet sizes, and distribution are of primary importance to improve fuel efficiency and lower gas emissions. We have developed an innovative computational method and models to make this atomization process more predictive: a multiscale, multiphase fluid simulation, using a volume-of-fluid method implemented in a large eddy simulation algorithm found in the new KIVA-hpFE, a finite element method flow solver for all flow regimes.
Nomenclature
Cp | = | specific heat capacity at constant P (J/kg · K) |
c | = | sound speed (m/s) |
E | = | total internal energy (J/kg) |
e | = | any element |
fs | = | surface tension force |
= | unit normal of the interface surface | |
P | = | pressure (Pa) |
T | = | temperature (K) |
tij | = | grid-scale (resolved scale) shear stress |
= | intermediate velocity | |
Ve | = | volume of computational element |
Greek symbols | = | |
ρ | = | density (kg/m3) |
β | = | artificial compressibility |
= | mass fraction | |
σ | = | surface tension coefficient |
= | Dirac delta function | |
κ | = | surface curvature |
μ | = | fluid viscosity ( |
= | turbulent eddy viscosity | |
ν | = | kinematic viscosity |
τij | = | subgrid-scale stress tensor |
ϕ | = | volume of fraction |
ϕE | = | elemental value for volume of fraction |
Nomenclature
Cp | = | specific heat capacity at constant P (J/kg · K) |
c | = | sound speed (m/s) |
E | = | total internal energy (J/kg) |
e | = | any element |
fs | = | surface tension force |
= | unit normal of the interface surface | |
P | = | pressure (Pa) |
T | = | temperature (K) |
tij | = | grid-scale (resolved scale) shear stress |
= | intermediate velocity | |
Ve | = | volume of computational element |
Greek symbols | = | |
ρ | = | density (kg/m3) |
β | = | artificial compressibility |
= | mass fraction | |
σ | = | surface tension coefficient |
= | Dirac delta function | |
κ | = | surface curvature |
μ | = | fluid viscosity ( |
= | turbulent eddy viscosity | |
ν | = | kinematic viscosity |
τij | = | subgrid-scale stress tensor |
ϕ | = | volume of fraction |
ϕE | = | elemental value for volume of fraction |