Combustion of droplets of liquid fuels: A review

Kinetics and convection in the combustion of alkane droplets

The most fundamental features of fuel-droplet combustion are observed in the spherical combustion of free fuel droplets. However, previous experiments have been influenced by natural or forced convection and by suspending filaments and, thus, have not revealed the true characteristics of fuel-droplet combustion. The authors have developed a successful technique for achieving spherical spherical combustion of free fuel droplets under a zero-gravity condition in a freely falling chamber. The behavior of free fuel droplets burning spherically was photographed with a movie camera and analyzed to determine the true characteristics of fuel-droplet combustion. The effect of the initial droplet diameter on the combustion characteristics was clearly established. The influence of filaments on the combustion of suspended fuel droplets has been also discussed, comparing the cases of free and suspended fuel droplets in spherical combustion.

Combustion of free fuel droplets in a freely falling chamber

The effect of initial droplet diameter on the burning rate of sooting fuels - n-heptane and 1-chloro-octane - was examined experimentally at low gravity. A 1.2s drop tower provided a low gravity environment to minimize buoyancy and achieve spherically symmetric flames for stationary droplets. Free-floating and fiber-supported droplets were burned, and both techniques gave matching results for droplets of similar initial diameter. Burning rate constants for both fuels were measured for a large number of droplets ranging from 0.4 to 1.1mm in initial diameter.

M.T. Monaghan

Papers

The influence of initial diameter on the combustion of single drops of liquid fuel