We investigate the interaction of thermonuclear flames in Type Ia supernova explosions with vortical flows by means of numerical simulations. In our study, we focus on small scales, where the flame propagation is no longer dominated by the turbulent cascade originating from large-scale effects. Here, the flame propagation proceeds in the cellular burning regime, resulting from a balance between...

After reviewing the background, this article discusses the recently discovered examples of hybrid propagating structures consisting of vortex dipoles and comoving gravity waves undergoing wave capture. It is shown how these examples fall outside the scope of the Lighthill theory of spontaneous imbalance and, concomitantly, outside the scope of shallow-water dynamics. Besides the fact that going...

A new approach to consider balance dynamics for modelling slow vortical motion is suggested within the rotating shallow water primitive equations. Instead of a traditional approach using divergence and ageostrophic vorticity as fast variables, the velocity is exactly expressed as a sum of the gradient part, described by a Bernoulli function, and the rest, an agradient part, proportional to the ...

We examine the horizontal wavenumber spectra of horizontal velocity and potential temperature collected by aircraft above the Pacific Ocean to determine whether gravity waves, quasi-two-dimensional (Q-2-D) turbulence, or vortical modes dominate atmospheric fluctuations at scale sizes of 1-100 km and altitudes of 212 km. We conclude from the study of Doppler-shifting effects that Q-2-D turbulenc...

[1] Airborne Doppler radar observations from the recent Tropical Cyclone Structure 2008 field campaign in the western North Pacific reveal the presence of deep, buoyant and vortical convective features within a vertically‐sheared, westward‐moving pre‐depression disturbance that later developed into Typhoon Hagupit. On two consecutive days, the observations document tilted, vertically coherent p...

The endwalls in a Taylor–Couette cell introduce adjacent boundary layers that interact with the centrifugal instability. We investigate the interaction between the endwall Ekman layers and the Taylor vortices near transition from nonvortical to vortical flow via direct numerical simulation using a spectral method. We consider a radius ratio of h50.75 in a short annulus having a length-to-gap ra...

The tip-clearance flow in axial turbomachines is studied using large-eddy simulation with particular emphasis on understanding the unsteady characteristics of the tip-leakage vortical structures and the underlying mechanisms for cavitation-inducing low-pressure fluctuations. Systematic and detailed analysis of the velocity and pressure fields has been made in a linear cascade with a moving end-...

The conditions of generation of vortical flows in fusion plasma are reviewed with particular interest for the role of the small scale vortices in the intermittency events of the internal transport barriers (ITB). Exact solutions are provided for stationary states.

Context. Extragalactic jets are inferred to harbor dynamically important, organized magnetic fields which presumably aid in the collimation of the relativistic jet flows. We here explore by means of grid-adaptive, high resolution numerical simulations the morphology of AGN jets pervaded by helical field and flow topologies. We concentrate on morphological features of the bow shock and the jet b...