Time-resolved measurements of supersonic fuel sprays using synchrotron X-rays

Area of Science:

• Combustion Science and Engineering
• Fluid Dynamics
• Materials Science

Background:

• Understanding diesel fuel spray behavior near the injector is critical for optimizing combustion efficiency and reducing emissions.
• The near-nozzle region is optically dense, making traditional optical diagnostic techniques ineffective for fuel distribution analysis.
• Previous studies lacked the resolution and detail to accurately characterize fuel distribution in this crucial area.

Purpose of the Study:

• To develop and validate a time-resolved radiographic technique for probing near-nozzle diesel fuel spray.
• To quantitatively determine fuel distribution in the optically impenetrable region close to the injector nozzle.
• To provide unprecedented detail for near-nozzle fuel spray studies.

Main Methods:

• Employed a time-resolved radiographic technique utilizing monochromatic synchrotron-generated X-ray absorption.
• Achieved a time resolution of better than 1 microsecond for capturing dynamic spray events.
• Focused on quantitative determination of fuel distribution in the immediate vicinity of a high-pressure single-hole diesel injector.

Main Results:

• Successfully developed a technique capable of quantitative fuel distribution measurements near the diesel injector nozzle.
• Achieved high temporal resolution, enabling the study of transient spray phenomena.
• Generated the most detailed dataset to date for near-nozzle fuel spray characteristics.

Conclusions:

• The developed time-resolved X-ray absorption technique is effective for quantitative analysis of near-nozzle diesel fuel sprays.
• This method overcomes the limitations of optical diagnostics in optically dense regions.
• The findings provide crucial data for improving diesel engine models and performance.