Evaporation Effects on Shock-driven Droplet Breakup at Hypersonic Conditions

Hypersonic vehicles must navigate through rain droplets and clouds of ice particles at

various altitudes, especially during take-off and landing. The impact of adverse weather on

hypersonic flights, which can disrupt the vehicle's flowfield and damage its surface, is not

well understood. The present study aims to enhance the understanding of simultaneous

aerobreakp and evaporation of rain droplets during their interaction with the transient

shocked flowfield induced by a hypersonic vehicle before the droplet impacts on its surface.

This study follows a Direct Numerical Simulations (DNS) approach to elucidate the effects

of evaporation on hydrodynamic instabilities and shock-driven droplet breakup in the post-

shock region. A "10 equation model" is developed to simulate shock-driven droplet breakup

and evaporation involving three components: liquid droplet, its vapor, and inert air. The

model enforces thermodynamic, mechanical, and chemical equilibrium among these

species, providing insights into evaporation's effects on hydrodynamic instabilities and

droplet breakup behavior at hypersonic conditions.