European High-Performance Infrastructures
in Turbulence

Collisions occur in atmospheric clouds and causes micron-sized water droplets to grow. Very few measurements have been made to detect these events, and little is known about how turbulence causes collisions, whether collisions lead to coalescence or break-up. In order to answers these questions, it is necessary to measure the distribution of radial relative velocities of droplet pairs, separated on scales on the order of the Kolmogorov length. The GTF3 is a unique facility that will allow us to obtain trajectories of droplets in very small measurement volume. We have developed a linear stereomatching model that fits well with previous measurements obtained in the same facility. We propose to apply this model to highly-resolved trajectories of droplets in a new experiment. As a proxy for the actual collision, we will look for droplets with approaching velocities, separated on the order of the Kolmogorov length. In a parallel effort, we will explore the possibility of using chemiluminescence and bioluminiscencein in collision experiment.