High-speed volumetric particle tracking measurements of unstable helical vortex pairs

Abstract We present results from an experimental study investigating pairs of helical vortices generated by a one-bladed rotor in hovering conditions. Time-resolved volumetric Lagrangian particle tracking measurements are conducted water tunnel to analyze the three-dimensional development vortex system. The specific tip design, which allows splitting single into two vortices, whose characteristics depend on geometric fin parameters. objective this procedure is modification structure, order minimize negative effects caused fluid–structure interactions applications involving rotors. Certain configurations affected centrifugal instabilities, result immediate pronounced growth cores. As consequence instability, secondary structures formed between unstable presence these accelerated break-up cores, causing them merge. In investigate influence trailing vorticity layer shed inner part blade, blade designs with different radial circulation distributions considered. able track evolution and structures, providing new insights instability closely spaced varying ratios.