scispace - formally typeset
Search or ask a question
Topic

Starting vortex

About: Starting vortex is a research topic. Over the lifetime, 4785 publications have been published within this topic receiving 100419 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: The motion of vortex rings with bilaterally symmetric initial shape is investigated theoretically and experimentally in this paper, where the induced velocity at each point on the vortex ring is computed from the Biot-Savart law.
Abstract: The motion of vortex rings with bilaterally symmetric initial shape is investigated theoretically and experimentally. The induced velocity at each point on the vortex ring is computed from the Biot‐Savart law. The induced velocity is related to the motion of the ring according to two different concepts: (1) Hydrodynamic vortex—the ring moves with the same velocity as the local fluid; (2) Rankine vortex—the local relative velocity produces lift and drag forces on the ring which serve to distort the ring. Observable vortex rings are produced by pulsing dyed fluid through a rectangular orifice and by staining the starting vortex behind ring wings of various shapes. Good qualitative agreement between the analyses and experiments is achieved.

45 citations

Journal ArticleDOI
TL;DR: The vortices emerging in rotating turbulent Rayleigh-Bénard convection in water at Rayleigh number Ra=6.0×10{8} are investigated using stereoscopic particle image velocimetry and by direct numerical simulation using the so-called Q criterion.
Abstract: The vortices emerging in rotating turbulent Rayleigh-Benard convection in water at Rayleigh number Ra=6.0×108 are investigated using stereoscopic particle image velocimetry and by direct numerical simulation. The so-called Q criterion is used to detect the vortices from velocity fields. This criterion allows distinguishing vorticity- and strain-dominated regions in the flow by decomposing the velocity gradient tensor into symmetric and antisymmetric parts. Vortex densities, mean vortex radii and mean vortex circulations are calculated at two horizontal cross-sections of the cylindrical flow domain and at several rotation rates, described by the Taylor number which takes values between 3.0×108 and 7.7×1010. Separate statistics are calculated for cyclonic and anticyclonic vortices. Vortex densities and mean vortex radii are mostly independent of the Taylor number except very close to the bottom and top plates where more vortices are detected when the Taylor number is raised (rotation increases). The vortex population close to the plate consists mostly of cyclones while further into the bulk of the domain a similar amount of cyclones and anticyclones is found. The cyclonic vortices contain more circulation than the anticyclones. The same vortex analysis of the simulation results at additional vertical positions revealed that the vortices are formed in a boundary layer on the plate with a thickness of approximately two Ekman lengths.

45 citations

Journal ArticleDOI
TL;DR: In this paper, the authors derived nonlinear equations describing the flute dynamics of rotating plasma and derived vortex solutions in the form of a shielded dipole vortex, similar to that found for nonlinear Rossby waves.
Abstract: Nonlinear equations describing the flute dynamics of rotating plasma are derived and solitary vortex solutions are obtained. The solution takes the form of a shielded dipole vortex, similar to that found for nonlinear Rossby waves. The nonlinear dispersion relation, relating propagation speed to vortex radius, is obtained. Vortex speeds are shown to take values complementary to the phase velocities of the linear modes of the system. The E×B circulation velocity of the plasma trapped in the vortex is comparable to the diamagnetic drift velocity in the equilibrium plasma.

45 citations

Journal ArticleDOI
TL;DR: In this paper, the linear stability of thin vortex rings is studied by short-wavelength stability analysis and the modified Hill-Schrodinger equation for vortex rings, which incorporates curvature effect, is derived.
Abstract: The linear stability of thin vortex rings are studied by short-wavelength stability analysis. The modified Hill–Schrodinger equation for vortex rings, which incorporates curvature effect, is derived. It is used to evaluate growth rates analytically. The growth rates are also evaluated by numerical calculation and they agree well with analytical values for small e which is the ratio of core radius to ring radius. Two types of vortex rings are considered: Kelvin’s vortex ring and a Gaussian vortex ring. For Kelvin’s vortex ring the maximum first-order growth rate is found to be 165256e. For the Gaussian vortex ring the first-order growth rate is large in the skirts of the vortex core. The first-order instability is significant for both vortex rings.

45 citations

Journal ArticleDOI
S. N. Brown1
TL;DR: The conically symmetric solution of the Eulerian equations of an incompressible fluid obtained by Hall, thought to be descriptive of flow properties in a leading-edge vortex, is generalized to include the effects of compressibility as discussed by the authors.
Abstract: The conically symmetric solution of the Eulerian equations of an incompressible fluid obtained by Hall, thought to be descriptive of flow properties in a leading-edge vortex, is generalized to include the effects of compressibility.

44 citations


Network Information
Related Topics (5)
Reynolds number
68.4K papers, 1.6M citations
92% related
Boundary layer
64.9K papers, 1.4M citations
90% related
Vortex
72.3K papers, 1.3M citations
90% related
Turbulence
112.1K papers, 2.7M citations
89% related
Laminar flow
56K papers, 1.2M citations
87% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202336
202278
20217
20207
20196
201815