EFFECT OF GAS PRESSURE AND TEMPERATURE ON THE REGIMES OF LIQUID DROPLET COLLISIONS

The paper presents experimental research findings for the critical conditions and integral characteristics of secondary atomization of liquid droplets when varying the gas medium pressure (0.9–5 atm) and temperature (20–200 °С). The experiments were conducted with water droplets with initial temperatures 20 °С and 80 °C to investigate the contribution of heating the liquid and its evaporation to the interaction conditions and characteristics. We varied the impact angles, sizes and velocities of droplets in a gas medium. Typical collision regimes were identified: bounce, coalescence, separation and disruption. Liquid droplet collision regime maps using the dimensionless linear parameter of interaction and Weber number were produced. Specific aspects of droplet collisions were established at different pressures and temperatures of the gas medium. The ratios of liquid surface areas before and after droplet disruption were calculated. The findings were compared with known data of other authors. Conditions were shown under which the gas pressure and temperature significantly affect droplet collision regimes and transition boundaries between them, as well as droplet collision outcomes.