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Updated: Aug 6, 2026
06:42
Magnetically Induced Rotating Rayleigh-Taylor Instability
Published on: March 3, 2017
Hydromagnetic instability in differentially rotating flows
1INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy.
Summary
Compressibility introduces a new instability in magnetized rotating flows, differing from standard magnetorotational instability. This new flow instability occurs under broad conditions, even with strong magnetic fields.
Area of Science:
- Plasma physics
- Astrophysics
- Fluid dynamics
Background:
- Magnetized differentially rotating flows are crucial in astrophysical and laboratory settings.
- Previous studies on incompressible flows revealed magnetorotational instability (MRI).
- The impact of compressibility on magnetized flow stability was not fully understood.
Purpose of the Study:
- To investigate the stability of compressible differentially rotating flows with magnetic fields.
- To identify new instabilities and their conditions.
- To compare these with existing models for incompressible flows.
Main Methods:
- Analysis of compressible fluid dynamics equations.
- Inclusion of magnetic field effects.
- Derivation of instability conditions.
Main Results:
- Compressibility significantly alters stability compared to incompressible flows.
- A new instability condition is identified: BsBphiOmega' != 0.
- This instability can occur regardless of the sign of Omega' (d Omega/ds).
- It functions even in strong magnetic fields that suppress standard MRI.
- Instability growth times can be as short as a few rotation periods.
Conclusions:
- Compressibility introduces a novel instability mechanism in magnetized rotating flows.
- This instability has broader applicability than standard MRI.
- It offers a new pathway for angular momentum transport in various physical systems.
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