Five Spray C nozzles were manufactured to intentionally produce cavitation within the hole. The holes were specified to be cylindrical with minimal hydro erosion, and to have the same flow number as converging, hydro-eroded Spray D nozzles. The actual geometry did not meet perfectly meet that specification, as the holes are actually diverging. Specifications and actual values are given below, along with full 3D geometry and needle movement measurements:

Specified and actual quantities for Spray C injectors of the ECN
Common rail fuel injector Bosch 3-22
Number of holes 1 (single hole)
Hole nominal diameter 0.200 mm
Hole outlet diameter (actual) 0.208 mm
Hole minimum diameter (actual) 0.187 mm
Nozzle K factor K=0
Nozzle shaping 5% hydro-erosion
Mini-sac volume (not including hole) 0.65
Flow with 10 MPa pressure drop 200 cc/min
Hole angular position axial

Nozzle geometry measurements have been made using x-ray computed tomography (CT) and optical microscopy. From these measurements, various surface (STL) files have been prepared, particularly for Injector 210037, and are available to use for CFD. The “Generation 2” measurements performed at Argonne National Laboratory at the Advanced Photon Source have better measurement resolution than previous commercial x-ray CT, and are therefore recommended/preferred. The original measurement and derived STL files are listed in Tables below.

Generation 2 x-ray CT measurements for Injector 210037:  
Measurements were performed in 2016 by Argonne National Laboratory offering resolution approaching 1 micrometer. Please find description and access to original STL datafiles and cite Matusik et al.
STL created for CFD Description Citation File size
Battistoni smoothed 2018 High detail on the original 100 MB file on the outside of the nozzle is smoothed, as this has no bearing on internal flow. Internal nozzle details are retained, with a resolution of approximately 3 um. Includes needle and some upstream downstream regions for CFD. Recommended for ECN7. ECN6 proceedings 24 MB
Hole and sac wire frame Axis-symmetric “wire frame” derived from Gen 2 geometry for simplified calculations. Radial distance is the “effective” radius for the flow area, rather than circle fits applied by Matusik et al. ECN6.14 LM Pickett, Sandia 4 KB
needle geometry Axis-symmetric “wire frame” for needle radius in a lifted state 0.4 mm from seat. 1 KB
Needle movement measurements for Injector 210037:  
Measurements were performed in 2017 by Argonne National Laboratory using phase-contrast imaging. Please find description, access to original data, and citation. One column of data is needle movement corrected for needle elasticity (see Yasutomi 2019 ), which is recommended for use at ECN7.
Needle movement Injector temperature Fuel pressure   Gas pressure Electronic command duration Hydraulic injection duration
C37 Needle Movement 24 C 1500 bar 1 bar 0.795 ms 2.45 ms
Generation 1 x-ray CT measurements for Injector 210037:  
Description: 3D volumetric slices and surface files were provided directly from North Star Imaging after measurements were performed in 2014. Sandia National Laboratories performed analysis and created an axis-symmetric wireframe for the needle and hole as given at the right of the table. Please reference Sandia and this website page for use of this data.
37 spray C 5p05um 0745
Slice from 3D CT at central cross-section of injector, with 5.05 μm per pixel. 2D axis-symmetric wireframe
download 3D stl (165 MB) wire frame hole and sac radius vs x (.csv)
download image wire frame needle radius vs x (.csv) with 0.4 mm lift
Optical microscopy of nozzle 210037 exit
Description: Microscopic imaging performed at Sandia National Laboratories with 0.2174 μm per pixel. Nozzle exit cleaned using compressed air. Analysis shows an exit area corresponding to an effective diameter of 208 μm. Measurements performed by Yongjin Jung, KAIST visitor. Cite this website page to reference this data.
Image Other details
download image Injector is oriented with fuel tube in up position per ECN convention.

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