  In high Reynolds number turbulent flows, energy dissipation refers to the
process of energy transfer from kinetic energy to internal energy due to
molecular viscosity. In large eddy simulation (LES) with one-equation
turbulence models, the energy dissipation process is modeled by a rate term in
the transport equation of the subgrid-scale (SGS) kinetic energy. Despite its
important role in maintaining a proper energy balance between the resolved and
SGS scales, modeling of the energy dissipation rate has received scarce
attention. In this paper, a SGS model belonging to the dynamic structure family
is developed based on findings from direct numerical simulation (DNS) studies
of decaying isotropic turbulence. The model utilizes a Leonard-type term, a SGS
viscosity, and a characteristic scaling term to predict the energy dissipation
rate in LES. A posteriori tests of the model have been carried out under
direct-injection gasoline and diesel engine-like conditions. Spray
characteristics such as penetration rates and mixture fractions have been
examined. It is found that the current SGS model accurately predicts
vapor-phase penetrations across different mesh resolutions under both gasoline
and diesel spray conditions, due to its correct scaling of SGS energy
dissipation rate with the SGS kinetic energy and LES fitter width. In contrast,
the classic model that is widely used in the literature predicts a scaling of
energy dissipation rate upon mesh resolution, exhibiting a noticeable mesh
dependence.
