Kerosene droplet size results

A two-color pyrometer has been used along with the phase-Doppler anemometer to simultaneously measure the local velocity and size of kerosene droplets and the temperature of burning soot mantle in a swirl burner.[648] The measurements were conducted within the flame brush that develops in the shear layer of a swirl-stabilized, gas-supported kerosene flame with a swirl number of about 0.19 and potential heat releases of 10.6 and 15.5 kW, respectively. The results showed that the maximum burning fraction of the droplets occurs adjacent to the region denoted as gas flame but the value ranges from 20 5 to 40 5% depending on the axial station, and decreases sharply across the shear layer. The flame mantle temperature was found to be independent of droplet diameter, which agrees with previous results in the literature. 

These results indicate that the enthalpy associated with air (and also steam) has an effect on the resulting droplet size. A larger droplet size with preheated air than steam reveals that there must be effects other than just the enthalpy associated with steam. Some of the possible factors include viscosity and density differences between the gases, and that water contained in steam may become miscible under these conditions. In this case, the large differences in the boiling points between the two fluids (water and kerosene) may lead to disruptive breakup of the liquid fuel, even at 10 mm, via rapid heat transfer from the flame. 

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