Criterion expressions for conditions and deceleration and subsequent entrainment of water drops by high-temperature gases

Abstract

On the basis of the results of experimental investigation of motion of water drops (from 50 to 500 μm in size) through high-temperature (about 1100 K) gases, we determine the conditions (in the form of criterion expressions) for deceleration of these drops and their entrainment by gases moving in the opposite direction. We introduce the Reynolds numbers of the dispersed and carrier phases as the characteristics of the given process. Optical particle image velocimetry (PIV) and interferometric particle imaging (IPI) methods, cross-correlation video complex with a pulsed laser, and a high-speed (105 frames per second) video camera are used. The initial velocities of the counter motion of water drops and gases are varied in ranges typical of many applications (0.5–5.0 and 0.5–2.5 m/s, respectively). The possibility of predictive simulation of drop deceleration conditions based in a relatively simple model of interaction of solitary elements of the disperse phase and high-temperature gases is demonstrated.