A Dynamic Droplet Breakup Model for Eulerian-Lagrangian Simulation of Liquid-fueled Detonation

Abstract

This study proposes a dynamic model to reflect the physical image of the droplet breakup process in two-phase detonation flows. This breakup model is implemented in a two-phase detonation solver developed based on an open-source computational fluid dynamic platform, OpenFOAM, and compared with three prevalent models (TAB, PilchErdman, and ReitzKH-RT model) under different droplet diameters in one- and two-dimensional detonation problems. The simulating results show that the present breakup model well predicts experimentally determined detonation parameters such as detonation velocities and post-wave temperature. In addition, the present model has the advantage of being free of the KH breakup time parameter, which is needed by the ReitzKH-RT model to fit the experimental data. The one-dimensional detonation simulations indicate that different breakup models have a slight impact on the detonation wave velocity because the droplet breakup process does not significantly affect the total heat release as long as it is sufficiently fast to sustain the detonation. However, the two-dimensional detonation simulations show that both the breakup model and the droplet initial diameter significantly affect the detonation cell size due to the different droplet distributions predicted by different models. The breakup length, which is the distance from the shock wave to the location at which sufficiently small child droplets appear, affects the chemical reaction zone thickness, which in turn affects the detonation cell size. A longer breakup length will result in a larger detonation cell size.