A New Quantitative 3D Imaging Method for Characterizing Spray in the Near-field of Nozzle Exits

Abstract : To assist in the development of more accurate models and understanding of liquid atomization, we have developed a new quantitative measurement technique to examine the dense near-field region of sprays using X-ray computed tomography (CT). An optimized spray CT system was designed using a modern conventional flat-panel tabletop conebeam X-ray CT with recommendations for further improvements in spatial resolution. Three-dimensional time-averaged liquid mass distributions have been obtained for scaled pressure swirl atomizers, which match the dimensionless parameters for typical spray application. The results reveal three-dimensional characteristics of nominally axisymmetric sprays and provide quantitative evaluation data for high-fidelity simulations. Furthermore, preliminarily comparisons have been made to standard optical measurements techniques such as Shadowgraphy and PLIF as validation.