A common method for maximizing energy conversion is to introduce particulate wastes (industrial, municipal, or sewer) into energy-harvesting equipment, such as steam boilers. Doing so, however, often requires the waste be provided in a viscous slurry form which is difficult to disintegrate for combustion. Steam-assisted atomization can, therefore, be beneficial, but the additional steam reduces boiler efficiency. Minimizing steam introduction thus becomes a primary motivation. Typical twin-fluid atomizers involve the assisting steam flowing on the outside of the assisted slurry; it is shown that this method produces unsatisfactory atomization at preferred steam flows. Inverting the feeds, such that the slurry is outside the steam, produces atomized slurry down to very low steam flows according to CFD simulations. The key is to allow interfacial unsteadiness to encourage a pulsing flow which amplifies the growth of instabilities. Reduced order models facilitate rapid design evaluations.
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