Measuring evaporation of micro-fuel droplets using magnified DIH and DPIV

This paper details the use of magnified digital in-line holography (MDIH) and digital particle image velocimetry (DPIV) to measure the evaporation rates of fuel micro-droplets undergoing heating. The technique can be used to measure instantaneous evaporation along an individual droplet trajectory, or if applied to a series of droplets, the average evaporation over a number of successive measurement locations. The advantage of this technique over traditional optical techniques is greater spatial resolution and depth of field for the high magnification factors used. An application of the technique to the evaporation measurement of diesel fuel droplets ranging from 10 to 90 μm is presented. Results reveal that similar to larger droplets, temperature plays the dominant role in evaporation processes, with little sensitivity to initial droplet size found for a peak reactor temperature of 660 K.