Love waves propagated in an axially symmetric heterogeneous layer lying between two homogeneous halfspaces

1967 ◽  
Vol 68 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Kehar Singh
Keyword(s):  
Love Waves ◽  
Axially Symmetric ◽  
Heterogeneous Layer

Disturbances in semi-infinite heterogeneous media generated by torsional sources. I

1972 ◽  
Vol 62 (2) ◽  
pp. 541-550
Author(s):  
R. S. Sidhu
Keyword(s):  
Heterogeneous Media ◽  
Formal Solution ◽  
Homogeneous Medium ◽  
Finite Depth ◽  
Free Boundaries ◽  
Axially Symmetric ◽  
Sh Waves ◽  
Reflected Waves ◽  
Buried Point ◽  
Heterogeneous Layer

abstract This paper studies the generation of axially symmetric transient SH waves in semi-infinite heterogeneous media in which μ and ρ vary with depth. The sources generating these waves are taken in the form of time-dependent torsional-body forces of finite dimensions. The solution is obtained using Hankel and Laplace transforms and Green's function. The disturbance from a buried point source of impulsive type is discussed in two cases, (a) μ = μo(1 + ɛz)2, ρ = ρo (1 + ɛz)2, (b) μ = μoe2az, ρ = ρoe2az. It is shown that, in contrast to the results for a homogeneous medium, in case (i), the wave reflected by the free surface generates secondary disturbances which trail behind the wave front and die out as t increases; the incident wave in this medium generates no such disturbance. In case (ii), however, both the incident as well as the reflected waves generate secondary disturbances. Formal solution for the disturbance in a heterogeneous layer of finite depth with stress-free boundaries is discussed in Appendix II.

Solar Internal Rotation and Dynamo Waves: A Two-Dimensional Asymptotic Solution in the Convection Zone

2000 ◽  
Vol 179 ◽  
pp. 379-380
Author(s):  
Gaetano Belvedere ◽  
Kirill Kuzanyan ◽  
Dmitry Sokoloff
Keyword(s):  
Magnetic Field ◽  
Asymptotic Solution ◽  
Internal Rotation ◽  
Convection Zone ◽  
General Idea ◽  
Dynamo Model ◽  
Axially Symmetric ◽  
Dynamo Action ◽  
Regeneration Rate ◽  
Dynamo Waves

Extended abstractHere we outline how asymptotic models may contribute to the investigation of mean field dynamos applied to the solar convective zone. We calculate here a spatial 2-D structure of the mean magnetic field, adopting real profiles of the solar internal rotation (the Ω-effect) and an extended prescription of the turbulent α-effect. In our model assumptions we do not prescribe any meridional flow that might seriously affect the resulting generated magnetic fields. We do not assume apriori any region or layer as a preferred site for the dynamo action (such as the overshoot zone), but the location of the α- and Ω-effects results in the propagation of dynamo waves deep in the convection zone. We consider an axially symmetric magnetic field dynamo model in a differentially rotating spherical shell. The main assumption, when using asymptotic WKB methods, is that the absolute value of the dynamo number (regeneration rate) |D| is large, i.e., the spatial scale of the solution is small. Following the general idea of an asymptotic solution for dynamo waves (e.g., Kuzanyan & Sokoloff 1995), we search for a solution in the form of a power series with respect to the small parameter |D|–1/3(short wavelength scale). This solution is of the order of magnitude of exp(i|D|1/3S), where S is a scalar function of position.

Unstable axially symmetric mhd flow between rotating boundaries

2001 ◽  
Vol 7 (2s) ◽  
pp. 19-25
Author(s):  
A.A. Loginov ◽  
◽  
Yu.I. Samoilenko ◽  
V.A. Tkachenko ◽  
◽  
...  
Keyword(s):  
Mhd Flow ◽  
Axially Symmetric
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