Metadata
Show full item recordShare this item!
The Role of Inertia in the Onset of Turbulence in a Vortex Filament
Language
EN
Article de revue
This item was published in
Fluids. 2023-01-02, vol. 8, n° 1, p. 16
English Abstract
The decay of the kinetic energy of a turbulent flow with time is not necessarily monotonic. This is revealed by simulations performed in the framework of discrete mechanics, where the kinetic energy can be transformed into ...Read more >
The decay of the kinetic energy of a turbulent flow with time is not necessarily monotonic. This is revealed by simulations performed in the framework of discrete mechanics, where the kinetic energy can be transformed into pressure energy or vice versa; this persistent phenomenon is also observed for inviscid fluids. Different types of viscous vortex filaments generated by initial velocity conditions show that vortex stretching phenomena precede an abrupt onset of vortex bursting in highshear regions. In all cases, the kinetic energy starts to grow by borrowing energy from the pressure before the transfer phase to the small turbulent structures. The result observed on the vortex filament is also found for the Taylor–Green vortex, which significantly differs from the previous results on this same case simulated from the Navier–Stokes equations. This disagreement is attributed to the physical model used, that of discrete mechanics, where the formulation is based on the conservation of acceleration. The reasons for this divergence are analyzed in depth; however, a spectral analysis allows finding the established laws on the decay of kinetic energy as a function of the wave number.Read less <
English Keywords
Turbulence cascade
Vortex stretching
Vortex bursting
Discrete mechanics
Conservation of acceleration
Helmholtz–Hodge decomposition
Inertial curvature