Mixed Lagrangian-Eulerian Simulation of Interaction between a Shockwave and a Cloud of Water Droplets

We present a numerical model suitable for simulation of shock or blast waves passing through a cloud of water droplets. The model takes into account the droplet breakup, radiation, and evaporation effects. The gas phase (a mixture of air and water vapor) is solved within an Eulerian framework with a set of compressible transport equations. The disperse phase (water droplets) is represented by a number of Lagrangian parcels of a specified size and mass distribution. The model has been verified with experimental data. The results show that for large (millimeter-sized) droplets with high Weber numbers, the breakup model is the most important part for accurate representation of the wave-droplet interaction phenomena, while for very fine droplets (1 \(\mu\)m or less), the evaporation effects are the strongest in the shockwave mitigation process. The radiative heat flux increase due to high droplet emissivity is found to be possible for an intermediate size water droplets (about 10–20 \(\mu\)m) in the case of continuous heat release.