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Updated: Jun 21, 2026
06:42
Magnetically Induced Rotating Rayleigh-Taylor Instability
Published on: March 3, 2017
Lyapunov instability of rough hard-disk fluids
Jacobus A van Meel1, Harald A Posch
1FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Summary
Dynamical instability in 2D rough hard-disk fluids is affected by rotation. Increased moment of inertia (I) reduces phase-space mixing (h{KS}) and alters chaos, with spatial localization persisting.
Area of Science:
- Statistical mechanics
- Dynamical systems theory
- Fluid dynamics
Background:
- Hard-disk models are fundamental in statistical mechanics.
- Dynamical instability and chaos are key properties of fluid systems.
- The role of rotational degrees of freedom in 2D hard-disk systems remains an area of interest.
Purpose of the Study:
- To investigate the dynamical instability of 2D rough hard-disk fluids.
- To characterize the influence of moment of inertia (I) on system dynamics.
- To analyze the relationship between phase-space mixing and rotational effects.
Main Methods:
- Lyapunov spectrum analysis.
- Kolmogorov-Sinai entropy (h{KS}) calculations.
- System simulation across various densities and moments of inertia (I).
Main Results:
- For small I, the Lyapunov spectrum shows distinct translation- and rotation-dominated parts.
- Increasing I leads to a merging of spectral parts and reduced phase-space mixing (h{KS}).
- Rotational effects enhance chaos at high densities but diminish it at low densities; spatial localization of perturbation vectors persists.
Conclusions:
- Rotational degrees of freedom significantly impact the dynamical instability of 2D rough hard-disk fluids.
- The moment of inertia (I) is a critical parameter governing the transition in dynamical behavior.
- Despite changes in chaos, perturbation localization remains a robust feature across different moments of inertia.
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