Near-Field Spray Characterization in a Pressurized Environment using High-Speed X-ray Imaging*

Sprays are commonly found in many industrial applications, from chemical applications for agricultural use to fuel injection in gas turbine engines to powder formation for 3D printing. Many of the processes like fuel injection occur in a pressurized ambient environment. Experimental visualization of the spray near-field region under these conditions is extremely challenging. To study high-pressure atomization, a Chamber for Assorted Pressurized Spray sUrveiLlancE, or CAPSULE, has been installed at the Advanced Photon Source (APS) at Argonne National Laboratory to perform high-speed X-ray flow visualization of the spray near-field. An airblast coaxial two-fluid atomizer was used in this study and white beam X-ray imaging focused on the nozzle exit. High-speed X-ray imaging revealed different atomization conditions as the swirl ratio, momentum flux ratio, and ambient pressure were increased. The variations were quantified through image analysis, which is only possible in the spray near-field with X-ray imaging.