Energy analysis of secondary droplet atomization schemes

This paper presents the energy analysis of the secondary atomization of droplets with various component compositions. We use the following four schemes together or separately: initial droplets colliding with each other, interaction with a solid wall, droplet transformation due to the oncoming air flow, and micro-explosive breakup of a droplet being heated. We consider the kinetic energies of primary (pre-atomization) and secondary (post-atomization) droplets and determine the heat spent on atomization. To show the need to atomize secondary droplets, we establish the differences between the heat released per unit time during the combustion of primary and secondary droplets. We also show that the least energy-consuming scheme is the one involving droplets colliding with each other and the most effective one in terms of fine aerosol production is the scheme with the micro-explosive droplet breakup. The latter may increase the liquid surface area more than tenfold. The research findings show that the energy spent on the atomization of fuel droplets is less than 1% of the energy released from their combustion. A combination of several atomization schemes becomes more effective with larger initial liquid droplets and their complex component composition.