Λ-vortex plays a critical role in the boundary layer transition process. In this paper, the mechanism of Λ-shaped rotational core formation is studied by DNS. The Blasius velocity profile is found to be the vorticity resource. The aggregation of vorticity (vortex filaments) is caused by the 2-D T-S wave. The mechanism of clustering of spanwise vorticity by 2-D T-S wave to form vortex tubes is s...

Comment on the paper of Jaffe et al (astro-ph/0503213) on evidence of vorticity and shear of the Universe We show that recent results in the paper of Jaffe et al on evidence of vorticity and shear of the Universe are incorrect. They fit WMAP data with certain Bianchi model which is known to have a vanishing vorticity. The performed fit of the shear is not reliable because the respective formula...

INTRODUCTION Theoretical analysis, experimental observations, and numerical simulations have all indicated that flame-vortex interactions play an important role in the propagation and extinguishment of turbulent flames in microgravity [1]. Most studies of flame-vortex interactions ignore the effects of gravity and experiments are usually conducted in Earth gravity. Recently, Sinibaldi et al. [2...

Banded structures” of macroscopic dimensions can be induced by simple shear flow in many different types of soft matter systems. Depending on whether these bands extend along the gradient or vorticity direction, the banding transition is referred to as “gradient banding” or “vorticity banding,” respectively. The main features of gradient banding can be understood on the basis of a relatively si...

In this study, the relation between the interior and the surface dynamics for nonlinear baroclinically unstable flows is examined using the concepts of potential vorticity. First, it is demonstrated that baroclinic unstable flows present the property that the potential vorticity mesoscale and submesoscale anomalies in the ocean interior are strongly correlated to the surface density anomalies. ...

Interaction between synoptic eddy and lowfrequency flow (SELF) has been the subject of many studies. In this study, we further examine the interaction by introducing a transformed eddy-potential-vorticity (TEPV) flux that is obtained from eddy-potential-vorticity flux through a quasi-geostrophic potential-vorticity inversion. The main advantage of using the TEPV flux is that it combines the eff...

The fundamental equations that model turbulent flow do not provide much insight into the size and shape of observed turbulent structures. We investigate the efficient and accurate representation of structures in two-dimensional turbulence by applying statistical models directly to the simulated vorticity field. Rather than extract the coherent portion of the image from the background variation,...

The main objective of the present study is to examine the characteristics of the vortical structures in a turbulent far wake using the wavelet multiresolution technique by decomposing the vorticity into a number of orthogonal wavelet components based on different central frequencies. The three vorticity components were measured simultaneously using an eight-wire probe at three Reynolds numbers,...