Structure and dynamics of the blue whirl

Abstract

The blue whirl is an unusual type of flame discovered accidentally in laboratory experiments and partly explained by previous experimental and numerical studies. Here, three-dimensional simulations are used to investigate the dynamics and structure of the blue whirl. Proper Orthogonal Decomposition (POD) is applied to identify the dominant flow structures, while Fast Fourier Transform (FFT) is used to analyze their frequency content. The findings reveal large- and medium-scale dynamics, including motion inside the domain, flapping, and puffing, offering a quantitative framework to understand the physical mechanisms behind the blue whirl’s stability and structure. The outcomes provide a robust foundation for future studies, including investigation of changes in background conditions, flow perturbations, and effects of tilting on structural stability and dynamics.