FN Archimer Export Format
PT J
TI An hydrodynamic shear instability in stratified disks
BT 
AF DUBRULLE, B
   MARIE, Louis
   NORMAND, C
   RICHARD, D
   HERSANT, F
   ZAHN, JP
AS 1:1;2:1;3:2;4:1,3;5:4,5;6:3;
FF 1:;2:;3:;4:;5:;6:;
C1 CEA Saclay, GIT, SPEC, DRECAM,DSM,CNRS,URA 2464, F-91191 Gif Sur Yvette, France.
   CEA Saclay, SPHT, DSM, CNRS,URA 2306, F-91191 Gif Sur Yvette, France.
   Observ Paris, LUTH, F-92195 Meudon, France.
   Inst Theoret Astrophys, D-6900 Heidelberg, Germany.
   Observ Paris, LESIA, F-92195 Meudon, France.
C2 CEA, FRANCE
   CEA, FRANCE
   OBSERV PARIS, FRANCE
   INST THEORET ASTROPHYS, GERMANY
   OBSERV PARIS, FRANCE
IF 4.223
TC 94
UR https://archimer.ifremer.fr/doc/00253/36469/35013.pdf
LA English
DT Article
DE ;accretion, accretion disks;hydrodynamic;instabilities;turbulence
AB We discuss the possibility that astrophysical accretion disks are dynamically unstable to non-axisymmetric disturbances with characteristic scales much smaller than the vertical scale height. The instability is studied using three methods: one based on the energy integral, which allows the determination of a sufficient condition of stability, one using a WKB approach, which allows the determination of the necessary and sufficient condition for instability and a last one by numerical solution. This linear instability occurs in any inviscid stably stratified differential rotating fluid for rigid, stress-free or periodic boundary conditions, provided the angular velocity Omega decreases outwards with radius r. At not too small stratification, its growth rate is a fraction of Omega. The influence of viscous dissipation and thermal diffusivity on the instability is studied numerically, with emphasis on the case when d ln Omega/d ln r = - 3/2 (Keplerian case). Strong stratification and large diffusivity are found to have a stabilizing effect. The corresponding critical stratification and Reynolds number for the onset of the instability in a typical disk are derived. We propose that the spontaneous generation of these linear modes is the source of turbulence in disks, especially in weakly ionized disks.
PY 2005
PD JAN
SO Astronomy & Astrophysics
SN 0004-6361
PU EDP Sciences
VL 429
IS 1
UT 000225732700006
BP 1
EP 13
DI 10.1051/0004-6361:200400065
ID 36469
ER

EF