Droplet behavior in overexpanded supersonic two-phase jets

The interaction of liquid droplets generated by spray atomization with high-speed co-flowing gas is interest in various applications including fuel injection, cooling, and surface coating. underlying processes involve interactions between the themselves, carrier gas. Additionally, they are influenced shock expansion waves present flows, accompanied resulting velocity pressure fluctuations. Non-intrusive diagnostics Shadowgraphy Phase Doppler Particle Anemometry, along flow simulations, used to study droplet behavior, characterized size changes, as a finely atomized propelled through supersonic, overexpanded jet structure. Measurements correlated train structure further obtained from simulation results. While observed be unaffected periodic increases decreases average size. Analysis using field estimated critical Weber numbers for breakup timescales dynamics, compared residence time flow, suggests that changes can attributed alternating coalescence breakup. two-dimensional involving converging diverging sections well spread sizes likely promote leading variation SMD. streamwise variations centerline caused not noticed velocity, which explained high Stokes number causing at behave ballistic particles moving Experimental measurements, results, their subsequent analyses show collision regimes established previous work ambient conditions deviations when subject conditions.