Mixture Formation in Spark-Ignition Engines

Abstract

I also express deep appreciation for the great support and courtesy shown by the following publishers and enterprises in permitting me to quote from copyright material including some illustrations:

Laser-Based Spatio-Temporal Characterisation of Port Fuel Injection (PFI) Sprays

“…Spray structures observed in this study are however, similar to the qualitative images seen in previous studies [1]. It is observed that a considerable portion of the spray near the injector is not atomized.…”

“…7 and 8, respectively. It is observed that though the instantaneous images show a wide spread of droplets, due to variations from spray-to-spray and presence of ligaments in the core region, the ensemble images resemble a 'pencil spray' as predicted by Lenz [1]. The breakup process is extremely complex with the interaction of the jets from the 2 or 4 nozzle holes.…”

“…These were obtained using a Zeiss microscope operated with the Axio Vision acquisition software. Being plate type injectors, the spray from these injectors is expected to be a 'pencil type' spray with a low divergence angle [1]. Preliminary experiments were required to obtain a basic idea of the spray structure since no prior data were available.…”

“…Fewer studies are found on small two-wheeler engines. Earlier studies on PFI sprays include those by Lenz [1], who discusses the different types of injectors and their operation characteristics: Pintle-type injectors give a cone-shaped spray while single-hole-type injectors form pencil-shaped sprays. Multi-hole-type injectors may either give a single spray (made up of several sprays) or a double spray (for use in 4-valve engines).…”

Hydrocarbon burning velocities determination using modified CFR engine

“…Fuel evaporation is a function of atmospheric air temperature, moisture, pressure [2,4,5] and intake manifold fuel droplet size, which is a function of either injection pressure and phase in a EFI, or venturi vacuum in a carburetor engine [5]. As SI engine combustion nature is turbulent, its flame speed depends on both fuel qualities like chemical composition and air-fuel relative ratio, and engine characteristics like cylinder pressure and temperature, which depend on compression ratio and spark advance [3,4] .…”