Effect of multiple shocks on enhancement/inhibition of droplet atomization

Shock-droplet interactions are critical in various high-speed multiphase flow applications, including supersonic combustion and shock-driven atomization, yet most existing studies focus on single-shock scenarios. Using high-fidelity numerical simulations, the current work compares the early-stage deformation and breakup dynamics of a liquid droplet (water) subjected to both single and double (identical) shock configurations at a shock Mach number of 2.4. The time-resolved droplet area evolution reveals that the presence of double shocks significantly delays droplet breakup and results in slower atomization rate compared to the single-shock case. Instantaneous pressure contours illustrate that the double shock induces symmetric compressive loading, leading to lateral flattening without substantial fragmentation, while the single shock causes asymmetric loading, rapid interface instabilities, and accelerated breakup. The double-shock scenario also generates elevated internal pressures, as seen from the amplified pressure gradients across the droplet. These findings highlight that counter-propagating shocks can substantially modify droplet deformation pathways and potentially extend droplet lifetime in shock-laden environments, which is critical for designing efficient high-speed multiphase systems.