Scaling Properties of the Lorenz System and Dissipative Nambu Mechanics

TL;DR

This paper explores how dissipation influences the Lorenz system's scaling properties, revealing a relation between dissipation strength and Reynolds number, and showing how weak dissipation leads to chaos.

Contribution

It introduces a scaling relation between dissipation and Reynolds number in the Lorenz system using Nambu mechanics, linking integrable limits to chaotic behavior.

Findings

Scaling relation between dissipation and Reynolds number

Weak dissipation controls route to chaos

Integrable limit corresponds to infinite Reynolds number

Abstract

In the framework of Nambu Mechanics, we have recently argued that Non-Hamiltonian Chaotic Flows in $ R^{3} $, are dissipation induced deformations, of integrable volume preserving flows, specified by pairs of Intersecting Surfaces in $R^{3}$. In the present work we focus our attention to the Lorenz system with a linear dissipative sector in its phase space dynamics. In this case the Intersecting Surfaces are Quadratic. We parametrize its dissipation strength through a continuous control parameter $\epsilon$, acting homogeneously over the whole 3-dim. phase space. In the extended $\epsilon$-Lorenz system we find a scaling relation between the dissipation strength $ \epsilon $ and Reynolds number parameter r . It results from the scale covariance, we impose on the Lorenz equations under arbitrary rescalings of all its dynamical coordinates. Its integrable limit, ($ \epsilon = 0 $, \ fixed r), which is described in terms of intersecting Quadratic Nambu "Hamiltonians" Surfaces, gets mapped on the infinite value limit of the Reynolds number parameter (r $\rightarrow \infty,\ \epsilon= 1$). In effect weak dissipation, through small $\epsilon$ values, generates and controls the well explored Route to Chaos in the large r-value regime. The non-dissipative $\epsilon=0 $ integrable limit is therefore the gateway to Chaos for the Lorenz system.