Effect of evaporation and surface tension on shock droplet interactions using detailed numerical simulations*

Evaporation plays an important role in liquid fuel droplet combustion [1] and is dictated by several factors including the particle size, gas temperature and shock strength. The size distribution of droplets is governed by breakup and coalescence processes, which are highly sensitive to surface tension. Extreme conditions encountered in combustion and detonations pose significant challenges to experimental investigations of these processes. In this work, we describe results from detailed numerical simulations of the evolution of a JP-10 liquid droplet in a heated air environment processed by an impinging shock wave. Simulations were performed for different shock Mach numbers and droplet diameters to isolate the effects of surface tension and evaporation on droplet breakup. A fifth order in space, WENO code, IMPACT was used to solve the Euler equations in Cartesian geometry with Adaptive Mesh Refinement and coupled to third-order Runge-Kutta scheme for time integration. The Level set method was used to track the interface between the liquid and gaseous phases and the Ghost Fluid Method (GFM), integrated with a multi-medium Riemann solver [2] was used to couple the two phases.