DROPLETS DISPERSION INFLUENCE IN THE VAPOR-AND-WATER FLOW ON CHARACTERISTICS OF THEIR MOVEMENT AND EVAPORATION IN THE COMBUSTION FLAME ZONE

The article presents experimental and numerical investigation results of droplets dispersion influence in the vapor-and-water flow on characteristics of their movement and evaporation in the combustion flame zone. High-performance computer systems, methods of high-speed video registration and also modern technical means on the basis of panoramic optical methods of multiphase flows diagnostic were used for the experimental researches. It is established that the systematic measurement errors of droplets sizes and velocities are no more than 1.5 and 2.1 %. Several characteristic modes of droplets coagulation at the movement through a flame are identified. The emergence reasons of each of the revealed modes are established and the corresponding images are presented. The typical videograms and velocity fields illustrating a turn of a vapordroplet flow by a counter flow of high-temperature gases are shown.With use of numerical simulation methods the distributions of temperatures and concentration of combustion products in the vicinityof water droplets are received. As a result of experimental and numerical results comparison the parameter characterizing a condition of braking and the subsequent droplets ablation is received. It is shown that for a choice of water dispersion parameters in a flame zone it is expedient to use the developed theoretical models and experimental results.