Precision Rayleigh jet sprays

Introduction

Sprays have a wide range of applications, from cleaning to agriculture to medical treatments. Spray technologies are key to many industrial processes, yet many current spray technologies suffer from insufficient control over the resulting spray parameters, such as the droplet size distribution. This is critical because the drop size determines whether a spray reaches its target in applications such as pharmaceutical drug inhalation and agricultural spraying. As trial-and-error spray development methods are reaching their limits, we need a new breakthrough to enable perfectly monodisperse sprays.

Previous Insights

I have previously shown that insights into the physics of sprays can lead to improved spraying and deposition methods. For agricultural sprays, I achieved the first detailed understanding of the strongly non-equilibrium processes that underlie spray formation. This understanding allows for a quantitative description of the drop size distribution in these sprays.

Future Directions

These insights pave the way to improving our understanding of sprays in general and translating it into a new generation of spray nozzles that produce highly controlled droplet size distributions, as urgently needed by a range of applications. The scientific challenge is to identify the complex nonequilibrium physics underlying liquid breakup and use these insights to devise entirely novel ways of controlling instabilities to achieve perfectly monodisperse sprays.

Methodology

We will combine breakthroughs in hydrodynamics to ‘tame’ the instabilities responsible for spray formation. This will involve:

1. Selective excitation of instability modes.
2. Novel nanofabrication methods for spray nozzles.
3. Studying drop coalescence and droplet trajectories in air.

Exploration of Mechanisms

We will elucidate spray mechanisms allowing for monodisperse sprays and explore the role of liquid composition in complex sprays. These fundamental breakthroughs will be tested in precision medicine and agriculture, two of the most important fields of spray use.