High-Speed Droplet Generator

The droplet generator utilizes a unique annular design to accelerate water droplets without atomizing them. An air intake manifold and guide vanes reduce turbulence and improve airflow into the annulus. A droplet generator at the center creates uniform water droplets up to 100 micrometer diameter. These droplets enter an angled outlet cone attached to the annulus. This cone uses its length and tapering internal diameter to gradually accelerate the droplets to speeds over 100 m/s. The smooth velocity transition maintains the droplets’ integrity. The droplets exit the cone in a narrow stream spanning 5° spread. The entire assembly connects to a ~110-120 psi system to generate the required pressure. While the droplet size and velocity range have been demonstrated, the exact parameters to achieve certain conditions are still being determined. The current lab prototype could be miniaturized or scaled for some applications. The technology and the related patent are now available to license. Please note that NASA does not manufacture products itself for commercial sale. Current methods for generating water droplets often require a tradeoff between droplet size and velocity. Small, atomized droplets can be accelerated to high speeds, while larger droplets tend to move slowly. This technology offers the best of both worlds: generating relatively large water droplets (up to 100 micrometer diameter) at high velocity (up to 115 m/s). The droplet generator was developed at NASA Glenn Research Center to provide a reliable way to evaluate icing effects and water's impact on aerospace components during flight tests and wind tunnel studies. By precisely controlling droplet size and speed, the technology ensures repeatable water droplet impact conditions for sensor calibration and materials testing. For icing studies, this technology solves challenges related to splashing, pooling, and other challenges that can impact the accuracy of hot wire anemometer probes. And unlike other sprayers which either atomize droplets or fail to achieve high velocity with large droplets, this novel design propels intact, well-defined droplets for more controlled experiments. With tunable parameters and a narrow spray area, the droplet generator may be valuable to aerospace research technology developers and various other fluid spray applications.