Polytechnic University of Valencia Congress, ILASS2017 - 28th European Conference on Liquid Atomization and Spray Systems

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High-speed X-Ray Phase Contrast Imaging of String Cavitation in a Diesel Injector Orifice
Ioannis Karathanassis, Phoevos Koukouvinis, Massimo Lorenzi, Efstathios Kontolatis, Zhilong Li, Jin Wang, N. Mitroglou, Manolis Gavaises

Last modified: 18-07-2017


The present investigation illustrates the temporally-resolved, phase-contrast visualization of the cavitating flowwithin an enlarged injector replica conducted at the ANL Advanced Photon Source. The flow was captured through side-view, x-ray radiographies at 67890 frames per second with an exposure time of 347ns. The orifice employed for the experiments has an internal diameter of 1.5mm and length equal to 5mm. A parametric investigation was conducted considering various combinations of the Reynolds and cavitation numbers, which designate the extent of in-nozzle cavitation. Proper post-processing of the obtained radiographies enabled the extraction of information regarding the shape and dynamical behaviour of cavitating strings. The average string extent along with its standard deviation was calculated for the entire range of conditions examined (Re=18000-36000, CN=1.6-7.7). Furthermore, the effect of the prevailing flow conditions on quantities indicative of the string dynamic behaviour such as the break-up frequency and lifetime was characterized and the local velocity field in the string region was obtained.

DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4996

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