Related papers: DC-driven positive streamer coronas in airflow
Both fluid and particle models are commonly used to simulate streamer discharges. In this paper, we quantitatively study the agreement between these approaches for axisymmetric and 3D simulations of positive streamers in air. We use a…
Plasma blobs are observed to be weak density enhancements as radially stretched structures emerging from the cusps of quiescent coronal streamers. In this paper, it is suggested that the formation of blobs is a consequence of an intrinsic…
Periodic Density Structures (PDS) observed in white-light coronagraphs represent a fundamental challenge to conventional solar wind paradigms. Through systematic analysis of multi-instrument observations and theoretical modeling, we…
Based on the properties of large-scale plume currents, an injection/suction control strategy is introduced to enhance the strength of plume currents and the turbulent transport of passive scalar in rotating plane Poiseuille flow. The…
This study analyses the main characteristics of the fully developed laminar pulsatile flow in a toroidal pipe as the governing parameters vary. A novel computational technique is developed to obtain time-periodic solutions of the…
Positive streamers are thought to propagate by photo-ionization whose parameters depend on the nitrogen:oxygen ratio. Therefore we study streamers in nitrogen with 20%, 0.2% and 0.01% oxygen and in pure nitrogen, as well as in pure oxygen…
We present a series of models for the plasma properties along open magnetic flux tubes rooted in solar coronal holes, streamers, and active regions. These models represent the first self-consistent solutions that combine: (1) chromospheric…
We study experimentally the statistical properties and evolution of circulation in a turbulent flow passing through a smooth 2-D contraction. The turbulence is generated with an active grids to reach $Re_{\lambda} \simeq 220$ at the inlet…
A streamer coupling theory is developed to describe the formation of homogenous emission, and the high moving speed of emission patterns in high pressure discharges. By considering the effects of both electron diffusion and electronic drift…
This paper reviews our growing understanding of the physics behind coronal heating (in open-field regions) and the acceleration of the solar wind. Many new insights have come from the last solar cycle's worth of observations and theoretical…
The growth of streamer discharges is determined at their heads, for individual streamers as well as in collective phenomena, such as streamer trees or coronas or streamer bursts ahead of lightning leaders. Some properties of the streamer…
A bypass transition scenario in a wind-stress driven aqueous flow is analysed using a temporally developing boundary layer model with accelerating surface drift velocity. The parameters of the model are selected to mimic a wave-tank…
The conditions were found when the gaseous medium demonstrates a unidirectional conductivity on a short time scale; a gas density discontinuity forms a kind of "gas-dynamic diode" that allows the plasma channel to propagate in one direction…
Particles moving along curved trajectories will diffuse if the curvature fluctuates sufficiently in either magnitude or orientation. We consider particles moving at a constant speed with either a fixed or with a Gaussian distributed…
The unsteady flow physics of wind-turbine wakes under dynamic forcing conditions are critical to the modeling and control of wind farms for optimal power density. Unsteady forcing in the streamwise direction may be generated by unsteady…
We study the dynamics of a self-propelled particle advected by a steady laminar flow. The persistent motion of the self-propelled particle is described by an active Ornstein-Uhlenbeck process. We focus on the diffusivity properties of the…
Aims: We investigate the atmospheric response to coronal heating driven by random flows with different characteristic time scales and amplitudes. Methods: We conducted a series of 3D MHD simulations of random driving imposed on a…
Recent observations of the solar corona with the LASCO coronagraph on board of the SOHO spacecraft have revealed the occurrence of triple helmet streamers even during solar minimum, which occasionally go unstable and give rise to large…
We study how external magnetic fields from 0 to 40 T influence positive streamers in atmospheric pressure air, using 3D PIC-MCC (particle-in-cell, Monte Carlo collision) simulations. When a magnetic field $\vec{B}$ is applied perpendicular…
We show that the spatio-temporal ElectroHydroDynamic (EHD) force production in surface AC-Dielectric Barrier Discharge (AC-DBD) actuators is strongly influenced by both the streamer regime during the positive phase and the micro-discharge…