PUFFING AND MICROEXPLOSION IN SECONDARY DROPLETS

Abstract

Secondary atomization of droplets (in the partial or full fragmentation regime) in multiphase and multicomponent fuel §ows is a promising technology that can minimize fuel consumption, improve the combustion dynamics, reduce anthropogenic emissions, stabilize fuel injection in a combustion chamber, and reduce the equipment wear [1, 2]. The most promising secondary atomization schemes involve droplet droplet collisions in intersecting fuel jets [3], droplet collisions with a solid surface in the form of walls, rings, meshes, and ledges [4], microexplosion, and pu©ng [5]. As a result of a microexplosion, the droplets of multiphase and multicomponent fuels break up to form an array of liquid fragments with a size of 1 100 μm [5]. The aim of this work is experimental research of pu©ng and microexplosion in secondary droplets. The number and radii of secondary fragments (child droplets) were analyzed by Shadow Photography (SP). Three approaches have been used to improve the accuracy of the experimental ¦ndings and to estimate their repeatability in a series of experiments. The measurements did not deviate by more than 5%. From the experiments conducted, the present authors managed to ¦nd the cause of signi¦- cant di¨erences in the characteristics of child droplets being formed in the course of microexplosion and pu©ng of two-liquid droplets for di¨erent formation regimes and identical heating conditions. After the research ¦ndings have been generalized, it became possible to determine the ranges of variation for the main parameters at which the maximum amount of child droplets with the required component composition could be obtained. In particular, the authorshave singled out the maps with multiple input parameters that can be used in the technologies of secondary fragmentation for the intensi¦cation of fuel mixing and combustion, puri¦cation of liquids, intensi¦cation of phase transitions, and heat exchange in power generation units.