Diesel Sprays Imaging Using X-Rays

Malave-Sanabria, A. Diesel Sprays Imaging Using X-Rays. University of Wisconsin-Madison, 2007.

Monochromatic synchrotron x-rays are used to measure fuel mass distribution in diesel sprays. X-ray measurements are used as an alternative to optical measurements, which typically fail due to multiple scattering in high density regions of the spray. In the x-ray photon energy range used (< 8 keV), some of the photons are absorbed by doped fuel but because of the very short wavelengths, there is very little scattering. The high density region near the tip of the nozzle is studied in detail to understand details of the injection process. The spray is mapped as it develops in time allowing us to estimate different spray properties such as fuel volume fraction, spray cone angle, and spray penetration with multi-orifice injection system.

Different injector tips were characterized with the tips varying in internal angle of convergence and in orifice machining. The spray was injected into different chamber environments. This study provides some insight on how the near-tip liquid spray from different geometry tips compare against each other, and also how they vary from hole to hole and tip to tip. A better understanding of the fuel-ambient gas interactions is achieved providing new data to develop spray models in the near nozzle region of the spray.