Beyond the Oberbeck-Boussinesq and long wavelength approximation
Journal article, 2023

We present the first simulations of a reduced magnetized plasma model that incorporates both arbitrary wavelength polarization and non-Oberbeck-Boussinesq effects. Significant influence of these two effects on the density, electric potential and E x B vorticity and non-linear dynamics of interchange blobs are reported. Arbitrary wavelength polarization implicates so-called gyro-amplification that compared to a long wavelength approximation leads to highly amplified small-scale E x B vorticity fluctuations. These strongly increase the coherence and lifetime of blobs and alter the motion of the blobs through a slower blob-disintegration. Non-Oberbeck-Boussinesq effects incorporate plasma inertia, which substantially decreases the growth rate and linear acceleration of high amplitude blobs, while the maximum blob velocity is not affected. Finally, we generalize and numerically verify unified scaling laws for blob velocity, acceleration and growth rate that include both ion temperature and arbitrary blob amplitude dependence.

arbitrary wavelength polarization

finite Larmor radius effects

gyro-fluid

gyro-kinetic

long wavelength limit

scrape-off layer transport

Boussinesq approximation

Author

Markus Held

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

M. Wiesenberger

Technical University of Denmark (DTU)

Nuclear Fusion

0029-5515 (ISSN) 1741-4326 (eISSN)

Vol. 63 2 026008

Implementation of activities described in the Roadmap to Fusion during Horizon Europe through a joint programme of the members of the EUROfusion consortium

European Commission (EC) (101052200), 2021-01-01 -- 2025-12-31.

Subject Categories

Applied Mechanics

Fluid Mechanics and Acoustics

Fusion, Plasma and Space Physics

DOI

10.1088/1741-4326/aca9e0

More information

Latest update

1/20/2023