Specific surface area measurements of diesel sprays were conducted using ultra-small-angle X-ray scattering at the 9-ID beamline of the Advanced Photon Source at Argonne National Laboratory. Injector orifice type, rail pressure, and ambient pressure effects were evaluated. The targeted sprays were created by three different single-hole nozzles fitted with duplicate light-duty common rail diesel injector bodies. One of the nozzles has been designed to cavitate under typical diesel operating conditions, while the other two nozzles are its non-cavitating analogues with nominally identical geometries. Measurements were performed in the near-nozzle region along the spray axis and across the width of the jet. These data provide information about, not only the rate of shear-driven atomization, but also the radial dispersion of the fuel droplets at each of the measured conditions. Additionally, when coupled with complementary measurements of the projected density, the data quantify the Sauter mean diameter of the fuel droplets in the probe volume. These specific surface area and Sauter mean diameter measurements can be applied to inform computational models of spray breakup that rely on droplet information in the near-nozzle region, where optical diagnostics have proven challenging.
- Diesel fuel spray
- Droplet surface area
- Sauter mean diameter
- Ultra-small-angle x-ray scattering
- X-ray radiography