New technique for producing highly uniform droplet streams over an extended range of disturbance wavenumbers

A recent discovery about a well-studied phenomenon leads to the formation of ultracoherent streams of liquid drops. A remarkably straightforward, although previously unreported, method of drop generation from capillary streams, which involves the imposition of an amplitude modulated sinusoidal carrier disturbance, is discussed. The amplitude-modulated disturbance results in the production of highly stable droplet streams over a previously unattainable range of wavenumbers. A decrease in the speed variation of the drops within the stream, which is a result of the amplitude modulation, is demonstrated over a range of nondimensional wavenumbers from 0.4 to 0.04. The nondimensional wavenumber is the ratio of stream circumference to disturbance wavelength. It is suggested that amplitude modulating the capillary stream’s disturbance may also decrease the diameter variation of the drops.