Statistical models of a droplet in the highly intermittent turbulence: breakup, dynamics and evaporation.
Abstract: In many problems of fluid dynamics, the Reynolds number is large and the flow structure is highly irregular – the localized velocity gradients may attain extreme values. This is a manifestation of strongly stretched and long-lived structures generated in narrow regions of the flow. The interactions of these structures, referred to as intermittency effects on turbulent microscales, lead to intense fluctuations of the energy dissipation rate, to violent accelerations of fluid particles, and to long-range auto-correlations. If such a flow is laden by droplets, the intermittency effects may have a strong impact on breakup, dynamics and evaporation of droplets. However in LES, the microscale turbulent properties are under-resolved. In this talk we will discuss how the intermittency effects in the residual scales can be introduced for practical simulations of atomizing and evaporating sprays. To this end, the new stochastic models of a liquid spray are developed and assessed.
