This study aims to elucidate the turbulent energy cascade and changes in vortex topology resulting from the oblique collision of a vortex ring with a vortex tube, governed by their initial circulations (CR = ${\mathrm{\Gamma }}_t/{\mathrm{\Gamma }}_r$, where ${\mathrm{\Gamma }}_t$ and ${\mathrm{\Gamma }}_r$ are the initial circulations of the tube and ring, respectively), at a Reynolds number (${\text{Re}}_{{\mathrm{\Gamma }}_r}$) of 12 000. The passing-through phenomenon is observed for CR = 0.1, where the vortex ring moves through the vortex tube without its deformation and generation of the small-scale vortices. At CR = 0.2, the stronger vortex ring entrains the weaker vortex tube in many rounds, leading to the breakdown of the entrained vortex tube parts into small-scale vortices, creating a turbulent flow with its energy cascade's slope nearly fitting to the Kolmogorov $k^{-5/3}$ slope. For higher CR = 0.5, the vortex reconnection partially occurs, where the vortex tube links with half of the vortex ring and wraps around another half of the ring, inducing a strong twisting of large-scale vortices and the formation of numerous small-scale vortices. For CR = 0.75, 1.0, and 1.5, the first reconnection creates a distorted vortex tube, and then this vortex reconnects itself to establish a new vortex ring and a new vortex tube. The turbulent flow at CR = 0.75 and 1.5 induced during the second reconnection is characterized by the $k^{-5/3}$ slope for the energy cascade, while not observed in the first reconnection. The change in the topology of the vortex structures, which later leads to the reconnection, is caused by the stretching and twisting of large-scale vortices. The induced small-scale vortices associated with turbulent flow development are observed in regions of high helicity, accompanied by the twisting of large-scale vortex structures. Furthermore, we observe that increasing ${\text{Re}}_{{\mathrm{\Gamma }}_r}$ promotes the formation of small-scale vortices and amplifies the deformation and instability of vortex cores.

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• Energy cascade
• Turbulence
• Turbulence simulations
• Vortex dynamics
• Vortex flows
• Vortex interactions
• Direct numerical simulations
• Lagrangian particle tracking