Skip to Main content Skip to Navigation
Theses

Instabilités et sources locales de turbulence dans les disques d'accrétion

Abstract : Angular momentum transport in accretion disks has been a highly controversial
debate for 30 years now. We present here a study of this transport, considering
some instabilities that can leads to developed turbulence in disks. The first
instability considered is the subcritical hydrodynamic instability. Our
numerical study shows that, although not directly observed in simulations, this
instability should lead to a very weak turbulent transport, and is probably not
relevant to explain disks observations. We then concider the stratorotational
instability, and we show using an analytical approach that it requires very
specific boundary conditions, which prevent this instability from appearing in
disks. Finally, we study the magnetorotational instability, including non ideal
MHD effect (resistivity and viscosity). We show numerically that these
effects, although small compared to ideal MHD terms, can have a strong impact on
the turbulence efficiency. This point emphasize the role of microphysic effects
in the saturation process, and the necessity to modelize these phenomena to get
a self-consistant accretion disk transport model.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00166016
Contributor : Geoffroy Lesur <>
Submitted on : Tuesday, July 31, 2007 - 11:50:55 AM
Last modification on : Friday, September 25, 2020 - 11:16:03 AM
Long-term archiving on: : Friday, April 9, 2010 - 12:14:55 AM

Identifiers

  • HAL Id : tel-00166016, version 1

Collections

CNRS | UJF | INSU | LAOG | OSUG | UGA

Citation

Geoffroy Lesur. Instabilités et sources locales de turbulence dans les disques d'accrétion. Dynamique des Fluides [physics.flu-dyn]. Université Joseph-Fourier - Grenoble I, 2007. Français. ⟨tel-00166016⟩

Share

Metrics

Record views

266

Files downloads

1169