AN EXPERIMENTAL PHASE DOPPLER ANEMOMETER STUDY OF ELECTROHYDRODYNAMIC ATOMIZATION

In this work, measurements of the size of the primary droplets generated by electrospraying 10 different liquids with different densities and surface tensions (measured by a tensiometer, Lauda LD1), viscosities, electrical conductivities (WTW LF530) and permittivities (capacitance bridge, Philips) were carried out. To measure the size of the droplets, a Phase Doppler Anemometer (Dantec/INVENT) was used. Gañán-Calvo et al. (1997) obtained on the basis of a theoretical model the so-called scaling laws, which permit the prediction of the spray current and droplet size. The empirical constants in these formulas were obtained from the experimental measurements. Two different behaviors were found, depending on the dimensionless parameter δμδ1/3=( 20γ2/κ2μ3Q)1/3. From our measurements, an intermediate regime with a much smaller slope is also found. This might also be due to the small flow rate, as the measurements which lie early below Gañán-Calvo’s fitting curve all satisfy the relation (Q/( r−1)1/2Q0)1/3<3.