ID 254

Spray Characteristics of a Rotary Atomizer

 

Abstract:

In this study, spray characteristics from rotary atomizers also known as slingers are investigated experimentally. This work is motivated by the demand for high energy density fuels such as fuel slurries. Aviation fuels loaded with high energy particles can exhibit variation in physical properties such as viscosity, density and surface tension. In the present study, spray characteristics of pure water, water ethanol blend, and water glycerol blend are investigated to understand the variation of physical properties on spray characteristics. A slinger of diameter 90-mm is studied with a single injection orifice of diameter 1-mm. The rotational speeds investigated in this study are 10000 and 15000 rpm. The jet visualization and spray characteristics such as breakup length and droplet size are measured using the shadowgraphy technique for both pure water and blends. For breakup length and jet visualization, imaging with a CCD camera with laser-induced fluorescent backlight is used. For droplet size measurements, a long-distance microscope (LDM) attached to a CCD camera with laser-induced fluorescent backlight is used. In this analysis, time variation of breakup length from the start of liquid feed is studied and images are acquired only after steady state of the liquid flow is achieved. Furthermore, the effects of rotational speed, liquid viscosity and liquid surface tension on SMD are studied. It is shown that non-dimensional SMD and Weber number exhibit a linear correlation in the log-log space for a range of liquid viscosity and surface tension.