The atomization and burning of liquid fuel sprays

Publisher Summary Atomization of the liquid fuel is carried out either by injecting the fuel through small orifices at high pressure or by mixing the fuel with high pressure air or gas. The most effective atomization is achieved when thin liquid sheets are formed that subsequently become unstable and then break up to form ligaments and large drops, which then break down further into small droplets. This chapter describes the twin-fluid and pressure jet atomizers. It examines the most recent experimental information that shows fundamental differences between liquid spray combustion and single droplet combustion. On the basis of this evidence, physical models are developed and an idealized spray flame is postulated. High-speed photography of droplets in sprays provides a direct measure of droplets in flight and obviates the introduction of probes into the spray. When a high-powered light source from a spark is focused on a small area within the spray, the shadow photographs of the droplets can be obtained, provided the spark duration is short, so as to freeze the droplet in flight.