X-ray radiography and phase-contrast imaging of the engine combustion network spray B sprays and injection

X-ray measurements of diesel sprays from two of the Engine Combustion Network (ECN) Spray B injectors were performed in three-hole nozzles which complemented both visible light measurements of these sprays and previous x-ray measurements of the axial single-hole ECN Spray A injectors. Both axial and lateral motions of the injector needle valve were measured with X-ray phase contrast imaging. The liquid mass distribution in room temperature sprays at elevated ambient pressure was determined using X-ray radiography. Measurements of both needle valve motion and spray distribution were done at both the standard Spray A/B conditions and with selected variations of injection pressure, ambient density, and injection timing. The needle valve motion for the Spray B injectors is quite similar to that of the Spray A injectors, though little lateral motion was observed in either Spray B injector. Compared to the sprays from the Spray A injectors, the sprays from Spray B penetrated more slowly in the near-nozzle region, demonstrated a broader, more uniform distribution in the transverse direction, and were significantly more variable with respect to time. These differences demonstrated the importance of studies with multi-hole nozzles to provide insight into applied diesel combustion.