Increasing concern for the environment and the impending scarcity of fossil fuels requires continued development in hydrocarbon combustion science. For compression-ignition engines, adding oxygenated compounds to the fuel can reduce noise, soot formation, and unburned hydrocarbons while simultaneously increasing thermal efficiency.
In order to reliably model and design compression-ignition engines to use new fuel blends, accurate spray characteristic data is required. In this study, the spray characteristics of various blends of the oxygenated compound di-n-butyl ether (DNBE) with standard EN590 Diesel fuel are presented, including spray cone angle and spray penetration length for both liquid and gas phases. The experiments were conducted in a spray chamber at ambient conditions of 50 bar and 800 K, simulating TDC conditions in a Diesel engine. Injection pressures were varied from 700-1600 bar. Mie-scatter and shadowgraphy techniques were used to measure the liquid phase and gas phase spray characteristics, respectively. The lift-off length and ignition delay is investigated using OH-measurement technique. The spray structure of the DNBE alone and its blends with Diesel fuel have shown a larger spray angle and shorter penetration length than with the pure Diesel fuel, providing improvements to atomization behaviour, and thus expected increases in performance.