Generalized Spectral Laws For The Energy And Enstrophy Cascades In A 2-Dimensional Turbulence
Title - Alternative
Helv. Phys. Acta
TWO-DIMENSIONAL TURBULENCE; FULLY-DEVELOPED TURBULENCE; NUMERICAL-SIMULATION; MULTIFRACTAL NATURE; KINETIC-ENERGY; SCALE; INTERMITTENCY; DYNAMICS; VORTICES; MODEL; Physics, Multidisciplinary
We consider generalized von Karman-Heisenberg-von Weizsacker type model for the inertial transfer to give generalized spectral laws for the energy and enstrophy cascades in a forced two-dimensional turbulence that provides a satisfactory unified description of the equipartition range and the inertial range for the energy cascade and the dissipation range and the inertial range for the enstrophy cascade. We will show that the equipartition range of the energy cascade and the dissipation range of the enstrophy cascade can be satisfactory modeled by a stationary continuous spectral cascading process. We will then discuss the intermittency aspects of the departures from the Batchelor-Kraichnan scaling laws and show that while the intermittency corrections within the framework of the beta-model are in qualitative agreement with the predictions made by the generalized spectral laws given in this article, intermittency by itself is unable to account fully for the equipartition spectrum of the energy cascade observed in laboratory experiments and the dissipative spectrum of the enstrophy cascade observed in laboratory and numerical experiments. We will discuss further fractal aspects of the enstrophy cascades, and show that for the enstrophy cascade, the fractal dimension rules not only the manner in which the cascading proceeds but also the point where it stops, while for the energy cascade the fractal dimension rules only the manner in which the inverse cascade proceeds and not the point where it stops.
Helvetica Physica Acta
Shivamoggi, B K., "Generalized Spectral Laws For The Energy And Enstrophy Cascades In A 2-Dimensional Turbulence" (1991). Faculty Bibliography. 1944.