Fabrication and Characterization of Micro-Orifices for Diesel Fuel Injectors

• Published in: SAE International journal of fuels and lubricants Vol. 1; no. 1; pp. 910 - 919
• Main Authors: Fenske, George, Woodford, John, Wang, Jin, El-Hannouny, Essam, Schaefer, Ronald, Hamady, Fakhri
• Format: Journal Article
• Language: English
• Published: Warrendale SAE International 01.01.2009; SAE International, a Pennsylvania Not-for Profit
• Subjects: Adhesion; Atomization; Coatings; Diesel; Diesel fuels; Electroless nickel plating; Emission standards; Fabrication; Fuel combustion; Fuel injection; Fuel sprays; Fuels; Hydrogen; Imaging; Injection; Nickel; Nozzles; Orifices; Particulates; Sprays; X ray imagery
• ISSN: 1946-3952; 1946-3960; 1946-3960
• DOI: 10.4271/2008-01-1595

Stringent emission standards are driving the development of diesel-fuel injection concepts to mitigate in-cylinder formation of particulates. While research has demonstrated significant reduction in particulate formation using micro-orifice technology, implementation requires development of industrial processes to fabricate micro-orifices with diameters as low as 50 μm and with large length-to-diameter ratios. This paper reviews the different processes being pursued to fabricate micro-orifices and the advanced techniques applied to characterize the performance of micro-orifices. The latter include the use of phase-contrast x-ray imaging of electroless nickel-plated micro-orifices and laser imaging of fuel sprays at elevated pressures. The experimental results demonstrate an industrially viable process to create small uniform orifices that improve spray formation for fuel injection.