Global and Local Measurements and Proper Orthogonal Decomposition of a Swirling Conical Liquid Sheet

In this work, ultra-high speed imaging of conical liquid sheets allows for non-invasive measurements of both global and local features of a swirling conical liquid sheet. The breakup of the swirling conical liquid sheet is visualized and the interface tracked between the conical liquid sheet and the ambient air. The applied experimental technique and the image processing technique capture planar images that are capable of tracking the dynamic behavior of the conical liquid sheet. Cone angle is shown to increase up to a critical Weber Number. The film length is obtained by identifying singular points in the signal response of the radial fluctuations. The results of the proper orthogonal modes indicate the existence of traveling waves on the interface of the swirling conical liquid sheet. Wavelength measurements of the traveling waves are comparable with linear instability analysis.