Convection in Water Droplet in the Presence of External Air Motion

Convection in a sessile droplet of water in a laminar air flow was studied. The experiments were conducted in the air velocity range U-1 = 2-5 m/s. The experimental data are compared with approximate numerical solutions and an approximate analytic solutionmade for small numbers Re for both the liquid and gas phase. It has been shown experimentally and theoretically that the maximum velocity in the droplet is proportional to the air velocity to the power of 1.5 and the droplet radius to the power of 0.5. An explanation of the fact that the experimental data are up to 50 times as small as the theoretical calculations has been suggested for the first time. The obtained dependencies may be useful for modeling the behavior of droplets in a spray.