Development of a reduced-order model of multiple vortex tornadoes from small-scale experimental data

In nature, a tornado can be composed of several subvortices (or suction vortices) revolving around the centre of their parent tornado. These multiple-vortex tornadoes are among the largest, strongest and most destructive tornadoes known to date. Despite their reputation, the fluid dynamics of multiple-vortex tornadoes remains poorly understood. As part of this work, the flow of two- and three-vortex tornadoes has been modelled and captured using a small-scale fundamental model. In particular, hypothetical attenuation or amplification processes between two- and three-vortex systems will be considered.

The objective of this project is to develop a reduced-order model of multiple-vortex systems based on the collected experimental data. We will explore the use of the so-called Zernicke polynomials as a mathematical basis onto which the data will be projected. The results will be compared to a proper orthogonal decomposition of the dataset as well as to analytical point vortex models. The flows will be studied based on their velocity potential and vorticity fields.