Abstract
We investigate the interaction of a Lamb-Oseen vortex and external turbulence by direct numerical simulations. Initial external turbulence (Rλ≅ 120) is produced by another numerical simulation based on the Fourier-spectral method. According to flow visualization, fine structures (worms) are stretched by the differential rotation of the columnar vortex, and spiral-like filament structures are formed around the columnar vortex. The columnar vortex is deformed by the vortex wave excited by the interaction between the columnar vortex and ambient turbulence. The flow field is analyzed statistically, and the energy transfer between the inside and the outside of the core of the columnar vortex is studied in detail.
