相关论文: High-Speed Acquisition of Free Vortex Formation

The shape of liquid surface in a rotating frame depends on the angular velocity. In this experiment, a fluid in a rectangular container with a small width is placed on a rotating table. A smartphone fixed to the rotating frame…

Steady-state turbulent motion is created in superfluid 3He-B at low temperatures in the form of a turbulent vortex front, which moves axially along a rotating cylindrical container of 3He-B and replaces vortex-free flow with vortex lines at…

A convenient method to create vortices in meta-stable vortex-free superflow of 3He-B is to irradiate with thermal neutrons. The vortices are then formed in a rapid non-equilibrium process with very distinctive characteristics. Two models…

This fluid dynamics video shows three-dimensional vortex formation process for plates in impulsive motion which is investigated experimentally by using defocusing digital particle image velocimetry (DDPIV). Rigid and flexible plate cases…

We present a fluid dynamics video on cavities created by explosions of firecrackers at the water free surface. We use three types of firecrackers containing 1, 1.3 and 5 g of flash powder. The firecrackers are held with their center at the…

The interaction of a shock wave with a spherical density inhomogeneity leads to the development of a vortex ring through the impulsive deposition of baroclinic vorticity. The present fluid dynamics videos display this phenomenon and were…

Large circular ice blocks up to 80 m of diameter have been observed on frozen river around the world. This rare event has been reported in a publication in 1993. This fascinating self-fashioned object slowly rotates at about 1$^o$ per…

Detailed study of torsional oscillator experiments under steady rotation up to 6.28 rad/sec is reported for a 4He superfluid monolayer film formed in 1 micrometer-pore diameter porous glass. We found a new dissipation peak with the height…

We carry out numerical simulations to investigate spontaneous vortex formation during a temperature quench of a superconductor film from the normal to the superconducting phase in the absence of an external magnetic field. Our results agree…

Fluidic transport in inverted T-shaped cavities with the flow entering through the top and exiting from the two bottom outlets experiences an interesting phenomenon that causes particles having density lower than that of the fluid medium to…

We report high-resolution measurements of three-dimensional (3D) turbulence in a rapidly rotating fluid. By decomposing the velocity field into a vertically averaged component and a three-dimensional residual, we show that each dominates…

We investigate the vortical dynamics generated during the forced exit of a circular cylinder through a quiescent free surface. While previous work on exit flows has largely emphasized cavity collapse and force generation, the formation and…

We study vortex ring formation arising from the interaction between a cavitation bubble and a confined air bubble in a cylindrical blind hole, using high-speed shadowgraphy imaging. As the cavitation bubble grows above the hole, it drives a…

This fluid dynamics video shows the impact of a hydrophobic sphere impacting a water surface. The sphere has a mass ratio of m* = 1.15, a wetting angle of 110 degrees, a diameter of 9.5 mm, and impacts the surface with a Froude number of Fr…

Energy dissipation and pressure fluctuations are features inherent to turbulent fluid motion, and the internal origin of spatial and temporal temperature fluctuations. By measuring local velocity, pressure or temperature, it is possible to…

We have demonstrated a new, accessible and economical technique, dubbed photostop, for producing high densities of trappable molecules. Direct measurements are presented of NO molecules produced with a narrow velocity distribution centered…

We use ultra-high-speed video imaging to look at the initial contact of a drop impacting onto a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by…

The idea that the knottedness (hydrodynamic Helicity) of a fluid flow is conserved has a long history in fluid mechanics. The quintessential example of a knotted flow is a knotted vortex filament, however, owing to experimental…

A dual-step cylinder is comprised of a large diameter cylinder (D) with low aspect ratio (L/D) attached co-axially to the mid-span of a small diameter cylinder (d). The fluid dynamics video presented in this investigation is used to…

We analyze dynamics of 3D coreless vortices in superfluid films covering porous substrates. The 3D vortex dynamics is derived from the 2D dynamics of the film. The motion of a 3D vortex is a sequence of jumps between neighboring substrate…