Dispersion relation as a channel of plasma turbulence evolution

Dispersion Relation for Alfvén Waves in a Viscous, Diffusive Plasma

Propagation of Alfvén waves in the solar plasma has been a topic of scientific interest for a long time. We have derived a dispersion relation ω4 + ω2[(ν2 + η2)k4 − v2 A k2] + iω(ν + η)v2 A k4 + (νηv2 A k6 + ν2η2k8) = 0 for shear Alfvén waves in a viscous and diffusive plasma. The MHD equations for viscous and diffusive plasma are ρ ∂ → v ∂t + ρ( → v .∇) →v= 1 μ (∇× → B)× → B +ρν∇ → v Momentum ...

Turbulence and Dispersion

Pair dispersion in turbulence

We study the statistics of pair dispersion in two-dimensional turbulence. Direct numerical simulations show that the pdf of pair separations is in agreement with the Richardson prediction. The pdf of doubling times follows dimensional scaling and shows a long tail which is the signature of close approaches between particles initially seeded with a large separation. This phenomenon is related to...

Parametric study of a viscoelastic RANS turbulence model in the fully developed channel flow

One of the newest of viscoelastic RANS turbulence models for drag reducing channel flow with polymer additives is studied in different flow and rheological properties. In this model, finitely extensible nonlinear elastic-Peterlin (FENE-P) constitutive model is used to describe the viscoelastic effect of polymer solution and turbulence model is developed in the k-ϵ-(ν^2 ) ̅-f framework. The geome...

The dispersion relation for magneto-plasma waves in multivalley semiconductors

The dispersion relation for plasma waves. propagating at an arbitrary angle to an external magnetic field, has been calculated on the basis of the Vlasov equation. The energy bands are assumed to be multivalley, non-parabolic and non-spherical. The case of strong degeneracy of the electron gas has been analysed.