Simulations of vortex tube dynamics reveal that the non-Gaussian nature of turbulent fluctuation originates in the effect of random advection. A similar non-Gaussian distribution is found numerically in a simplified statistical model of random advection. An analytical solution is obtained in the mean-field case.

Abstract In this paper, we investigate the formation of Rotating Vortex Rope (RVR) using scale-resolving methods, SAS and Wall-Modeled LES (WMLES). We compare results from these simulation methods with experimental data Francis-99 workshop. This comparison shows that general features RVR can be captured both methods. However, WMLES would lead to a better quantitative agreement between velocity ...

BACKGROUND The rostellum, a projecting part of the gynostemium in orchid flowers, separates the anther(s) from the stigma and thus commonly prevents auto-pollination. Nonetheless, as a modified (usually distal) portion of the median stigma lobe, the rostellum has been frequently invoked of having re-gained a stigmatic function in rare cases of orchid auto-pollination. Here it is shown that a ne...

Because of the unequal diameter between pulse tube and heat exchangers at two sides, fluid entering from exchanger easily forms a complex disturbing flow in tube, which causes energy loss affects performance refrigerator. This study proposes numerical model for predicting transfer characteristics refrigerators. Three cases adding conical transitions are studied, results indicate that transition...

This paper presents a numerical comparison of two regularizations of the Euler equations, namely, the vortex blob regularization and regularization by physical viscosity. The initial condition is a flat vortex sheet whose vorticity has been smoothed by convolution. The sheet rolls up into a vortex pair. We compute the frequency of oscillations in the core vorticity and scale it using results fo...

fabrication, characterization and application of micro-/nano-rods/wires are among the hottest topics in materials science and applied physics. micro-/nano-rod-based structures and devices are developed for a wide-ranging use in various fields of micro-/nanoscience (e.g. biology, electronics, medicine, optics, optoelectronics, photonics and sensors). it is well known that the structure and prope...

Explicit radius for nearly parallel vortex filaments in equilibrium 1 Geophysical research has focused on flows, such as ocean currents, as two dimensional. Two dimensional point or blob vortex models have the advantage of having a Hamilto-nian, whereas 3D vortex filament or tube systems do not necessarily have one, although they do have action functionals. On the other hand, certain classes of...

Experiments were performed to analyze the interaction of an explosively driven shock wave and a propane flame. A 30 g explosive charge was detonated at one end of a 3-m-long, 0.6-m-diameter shock tube to produce a shock wave which propagated into the atmosphere. A propane flame source was positioned at various locations outside of the shock tube to investigate the effect of different strength s...