A phenomenological model for near-nozzle fluid processes: Identification and qualitative characterisations

It is well established that emissions and inefficiencies primarily arise from localised fuel rich regions, which do not undergo complete combustion. In order to achieve significant reductions in NOx soot, modern engines employ multiple injection flow rate profiling strategies. However, during the end of each event, needle restricts internal fuel, rapidly reducing inertia emerging spray. Atomisation inhibited large fluid structures are released into cylinder. Once subsides, films remain on nozzle surface cycle. Fuel residing cavities emerges as cycles progresses, amalgamating with spray deposited films. The surface-bound presents an ideal environment for deposit forming reactions a medium precursors adhere onto. better understand these processes we performed measurements transients inside optical reciprocating rapid compression machine, using high-speed long-distance microscopy obtain detailed characterisations injector. We summarise our observations new phenomenological model describes uncontrolled release over entire engine This identifies micro-scale lead ejection, accumulation vaporisation in-between events. Characterisation critical, transient can support mitigation strategies inhibit pollutants formation injector deposits.