RESUMO

It is experimentally demonstrated that an intact liquid jet can be induced to atomize by imparting periodic external forcing at the jet nozzle. The induced atomization can take place only in small discrete bands of the forcing frequency. In these bands of frequency, the external forcing appears to promote a new kind of interfacial instability that, instead of producing the usual large Rayleigh drops, breaks the outer layer of the jet into droplets much smaller than the jet diameter. The core of the jet remains unatomized. The maximum power delivered to the nozzle is 2.7 W. This small power input appears insufficient to atomize the entire jet. At the same exciting frequency, the induced atomization produces smaller droplets for fluids with lower surface tension. For the same liquid, the atomizer can produce different sizes of droplet ranging from 8 to 40 μm by use of different forcing frequencies ranging from 17 to 100 kHz. Thus, the atomizer is capable of rendering tailored atomization.