The effect of gas and water droplet temperature on characteristics of water-droplet deformation at moderate velocities of droplet movement

An experimental study has been performed on the effect of the temperature of gas and water droplets (3–6 mm in size) on deformation of water droplets that move with a moderate velocity (up to 5 m/s). A high-speed videocamera (recording at up to 10⁵ fps) and a cross-correlation videocomplex were used. The droplet temperature varied in the range of 285–360 K. For gaseous mediums, air at a temperature of 280–300 K and condensed substance combustion products at a temperature about 1100 K were used. Typical deformation cycles were found. Their length, duration, and amplitude were calculated. The time a shape of droplet transforms into a new shape and the time the droplets retain their shape as they move through a gas medium have been determined. Approximating correlations for the basic characteristic of deformation under various heating or cooling conditions in a water droplet–gas system were derived.