Polar vortices on Mars provide case-studies to aid understanding of geophysical vortex dynamics and may help to resolve long-standing issues regarding polar vortices on Earth. Due to the recent development of the first publicly available Martian reanalysis dataset (MACDA), for the first time we are able to characterise thoroughly the structure and evolution of the Martian polar vortices, and he...

The motion of 100 point vortices in a circular cylinder is simulated numerically and compared with theoretical predictions based on statistical mechanics. The novel aspect considered here is that the vortices have greatly different circulation strengths. Specifically, there are 4 strong vortices and 96 weak vortices, the net circulation in either group is zero, and the strong circulations are f...

An intensive experimental investigation was conducted to study the effect of vertical tail, single and twin (with different cant angles) on the flow field and the corresponding aerodynamic forces and moments of a model of a fighter A/C. Aerodynamic forces under different flight conditions and different vertical tail settings were measured in a supersonic wind tunnel. Furthermore, effects of ver...

Several studies show that the Low-Frequency Noise (LFN) of wind turbines could have harmful effects on human health even when it is infrasound. In traditional classifications, the LFN of upwind turbines is referred only to steady thickness and steady loading sources, and the effect of vortices is considered negligible. In this study, the LFN of a horizontal axis wind turbine is simulated in win...

When three or more plane waves overlap in space, complete destructive interference occurs on nodal lines, also called phase singularities or optical vortices. For super positions of three plane waves, the vortices are straight, parallel lines. For four plane waves the vortices form an array of closed or open loops. For five or more plane waves the loops are irregular. We illustrate these patter...

The influence of disorder on the transport of quantum vortices in one-dimensional arrays of Josephson junctions was studied experimentally. The vortices localize in disordered arrays for small vortex densities resulting in a vanishing transport at low temperatures, whereas, in a periodic array, transport remains possible. For large vortex densities the mobility of vortices is maintained in the ...

The motion of vortices in an anisotropic superconductor is considered. For a system of well-separated vortices, each vortex is found to obey a law of motion analogous to the local induction approximation, in which velocity of the vortex depends upon the local curvature and orientation. A system of closely packed vortices is then considered, and a mean field model is formulated in which the indi...

It is shown that a symmetrical vortex pair consisting of equal and opposite vortices approaching a plane wall at right angles must approach the wall monotonically in the absence of viscous effects. An approximate calculation is carried out for uniform vortices in which the vortices are assumed to be deformed into ellipses whose axis ratio is determined by the local rate of strain according to t...

The wavelet-based vector multiresolution technique was proposed and applied to the post-processing of PIV results for identifying the multi-scale turbulent structures. By analyzing the instantaneous streamlines and vorticity fields of various scales the important information on the multi-scale flow structures was obtained. The large-scale vortices or coherent structures with a central scale of ...

Aircraft wake vortices can pose a threat, especially in the terminal environment where aircraft operate in close proximity. Vortex separation standards preclude hazardous encounters, but are oftentimes very conservative. A key to increasing airport capacity is to know when vortices are not a hazard so that aircraft can land and take off with closer intervals. A conference was held in London to ...