Mechanical Engineering, Chemical and Biological Engineering
Journal or Book Title
Atomization and Sprays
Coaxial atomizing sprays are used in industries from gas turbines to food processing. Spray dynamics depend heavily on the primary breakup (near-field) region. The near-field region is challenging to study because it contains thick liquid that is impenetrable to visible light. However, X-ray radiographs are capable of penetrating the dense liquid region, providing insight that is unavailable from visible light testing methods. This study modifies a method used in previous studies for determining the mass-averaged axial velocity from a narrow-angle, injection spray, into a method for studying the mass-averaged axial velocity from a wide-angle, constant spray. Experiments at the Advanced Photon Source at Argonne National Laboratory provided focused-beam X-ray radiographs along the spray. Results showed that the mass-averaged axial velocity along a coaxial spray increased linearly with axial distance from the nozzle for varying momentum ratios. The slope of the velocity-distance relation also increased linearly when plotted as a function of gas Reynolds number. Spray velocity is often considered for individual droplets or for the centerline, but not as a mass-averaged property. However, these results show that the mass-averaged axial velocity has predictable behavior in the near-field region for the conditions that were tested in this study.
Bothell, Julie K.; Morgan, Timothy B.; Kastengren, Alan L.; and Heindel, Theodore J., "Determining Spray Axial Velocity From Focused X-ray Radiography" (2020). Mechanical Engineering Publications. 445.
Available for download on Thursday, October 21, 2021