English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The shear flow influences the stability of magnetohydrodynamic (MHD) waves.In the presence of a dissipation mechanism, flow shear may induce a MHD waveinstability below the threshold of the Kelvin-Helmholtz instability (KHI),which is called dissipative instability (DI). This phenomenon is also callednegative energy wave instability (NEWI) because it is closely related to thebackward wave which has negative wave energy. Considering viscosity as adissipation mechanism, we derive an analytical dispersion relation for the slowsausage modes in a straight cylinder with a discontinuous boundary. It isassumed that the steady flow is inside and dynamic and bulk viscosities areoutside the circular flux tube under photospheric condition. When the twoviscosities are weak, it is found that for the slow surface mode, the growthrate is proportional to the axial wavenumber and flow shear, consistent with inthe incompressible limit. For a slow body mode, the growth rate has a peak atcertain axial wavenumber and its order of magnitude is similar to surface mode.The linear relationship between the growth rate and the dynamic viscosityestablished in the incompressible limit develops nonlinearly when the flowshear and/or the two viscosities are sufficiently strong.

Dissipative Instability of Magnetohydrodynamic Sausage Waves in a Compressional Cylindrical Plasma: Effect of Flow Shear and Viscosity Shear