CAREER: Disruption and Vaporization of Superheated Droplets in Compressible Flow

University Of Washington, Seattle WA

Investigators

Abstract

Abstract - CTS-9733830 Hermanson, James C. The breakup and vaporization of liquid droplets in a high-speed gas stream occurs in two-phase flows, spray drying, rocket nozzle flow, liquid fuel injection, and steam turbine blade erosion. Considerable practical advantages in many applications could be realized if high levels of dispersion and rapid mixing were achieved. One technique is that of flash vaporization which involves violent disruption and vaporization of superheated liquids. Most of the extant literature is focussed on incompressible flows and is not applicable to compressible flows, which are found in supersonic combustors. The physics of superheated liquid droplet disruption, vaporization, and fuel/air mixing are not well established. The proposed research program is a comprehensive, experimental investigation of the fundamental physics of superheated liquid fuel disruption and vaporization in supersonic flow, where the entire volume of the droplet is brought to a high level of superheat to promote flash vaporization. This work will be a first step towards achieving a fundamental understanding of the behavior of superheated liquid fuel sprays in compressible flow, with particular attention paid t the different instability mechanism which affect the droplet history. Droplets will be injected into a supersonic stream and their acceleration and subsequent vaporization will be examined primarily by planar laser-induced fluorescence and laser-spark schlieren/shadowgraphs.