Ecole doctorale de Physique de la région Parisienne (ED107)

136 Inertial modes in slowly rotating stars : An evolutionary description
V ϕ
2
1.5
1
0.5
θ = π/2
θ = 53π/96
θ = 29π/48
θ = 2π/3
θ = 19π/24
θ = 37π/48
θ = 5π/6
θ = 85π/96
θ = 15π/16
θ = π
V ϕ
0.4
0.3
0.2
0.1
0
0.8 0.9
ξ / R
1
0
0 0.2 0.4 0.6 0.8 1
ξ / R
Figure 4.21 – ϕ component of the velocity versus the radius for several values of ϑ. We
can see the main part of the velocity is concentrated in a region near the surface and close
to the equator. This “snapshot” of the profile was taken at a moment when the derivative
versus the radial coordinate of the velocity is quite huge at the surface.
V θ
0
-5
-10
θ = π/2
θ = 53π/96
θ = 29π/48
θ = 2π/3
θ = 19π/24
θ = 37π/48
θ = 5π/6
θ = 85π/96
θ = 15π/16
θ = π
V θ
0
-0.2
-0.4
-0.6
-0.8
0.8 0.9
ξ / R
1
-15
0 0.2 0.4 0.6 0.8 1
ξ / R
Figure 4.22 – ϑ component of the velocity versus the radius for several values of ϑ.
Here the concentration of the motion is higher than in the previous calculation. βn was
0.4 in Figure 4.21 and is now 0.8. Moreover, this calculation lasted three time longer.
Nevertheless, note that here we did not choose to draw the profile when the derivative is
huge but just drew it at the final instant.