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Showing 1 to 20 of 27 for “"Vortex pair"”.
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Interaction of a vortex pair and a free-surface : numerical simulation
The interaction between a submerged vortex pair with a deformable free-surface in a viscous, incompressible fluid is directly simulated and the flow is thoroughly analyzed. This is a time-dependent nonlinear free-surface problem which we solve numerically by integrating the two-dimensional …
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Surfactant effects on the interaction of a three dimensional vortex pair with a free surface; and,
… flow is in the form of two modulated finite-core vortex tubes parallel to the free surface. The vortex tubes break down via instability and helical vorticity is generated. The most prominent feature at the surface is that associated with the connection of helical vorticity to the free surface. For …
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The source and evolution of turbulence in trailing vortex pairs
… the experimental study of two different trailing vortex pairs has been conducted to obtain a more complete understanding of the turbulence structure of these flows. Statistical and spectral results, as well as filtered results and estimates of the effects of vortex wandering on the characteristics …
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Vortex Ring Collision with Free-Slip and No-Slip Wall
Vortex ring collision on wall explains azimuthal instability, stretching, vorticity and wall turbulence in a simplified way, required in many applications. Present study performs high Reynolds number (2500 and 4000) simulations of vortex rings approaching no-slip and free-slip walls for different …
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Investigations of Injectors for Scramjet Engines
… the injection point where the counter-rotating vortex pair (always associated with transverse injection in a crossflow) is not yet formed, and the deposition of baroclinic generated of vorticity is the highest. The final investigation concerned with the interaction of the usual vortex structure …
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Compressible Hydrodynamics of Few Body Optical Vortices
… fluid density and phase gradients at the vortex location. However, we find that these gradients alone are insufficient for describing vortex motion. Vortex ellipticity plays a crucial role in vortex dynamics in two-dimensional fluids, particularly during nucleation and annihilation events …
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Planar Laser Induced Fluorescence Experiments and Modeling Study of Jets in Crossflow at Various Injection Angles
… importance and structure of the counter rotating vortex pair and general flow field turbulence was highlighted by cross validation between CFD and experimental results.
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Large eddy simulations of turbulent flows on graphics processing units: application to film-cooling flows
… away from the surface to be cooled due to mutual vortex induction by the counter-rotating vortex pair embedded in the jet, resulting in decreased cooling at the surface. To counteract this, a micro-ramp vortex generator was added downstream of the film-cooling jet, which generated near-wall …
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Observation and Measurement of the Growth of the Primary Instabilities of the Richtmyer-Meshkov Instability and Observation of Secondary Instabilities
… gas column; that is, the counter-rotating vortex pair and the central spike; and the observation of secondary instabilities within the primary instability. The formation of the instabilities is the result of a standing normal shock wave of air interacting with a cylindrical column of sulfur …
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The turbulent structure of the jet in cross-flow
… were performed in the Counter-rotating Vortex Pair (CVP) plane for a high velocity ratio and jet Reynolds number. Statistical measurements at various downstream locations and velocity ratios are presented. Probability density functions of the streamwise vorticity field showed that each …
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Hydrodynamics of magnet-coil actuated robotic fish
… tail beat from the bang bang control creates vortex pairs at each start or stop motion of the caudal fin. Moreover, the wake structure from the shark Aquabot tail beat creates a wake structure similar to live dogfish sharks. Since the design of the Scuba Fish allowed more control over the …
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The turbulence structure of trailing vortex wakes
… of isolated vortices and counter-rotating vortex pairs. In the first part, the turbulence structure of an isolated vortex was studied using three-component velocity measurements. Vortices were generated using two symmetrical airfoils. Measurements were made in cross-sectional grids and …
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Comparison Of Square-hole And Round-hole Film Cooling: A Computational Study
… of a film cooling hole, a so-called horseshoe vortex structure consisting of a pair of counter-rotating vortices is formed. This vortex formation has an effect on the distribution of film coolant over the surface being protected. The fluid dynamics of these vortices is dependent upon the shape …
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The effect of wing flexibility on ride comfort in formation flight
… an aerodynamic model, based on the classical Vortex Lattice Method (VLM) and structural and inertial models defined by stiffness and mass matrices. The VLM code was validated for both large aspect ratio wings with low frequencies in unsteady aerodynamic conditions, as well as swept wings in …
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Simulation and experimental study of double holes film cooling
… caused by the formation of the Counter Rotating Vortex Pair (CRVP) which commonly discovered in the Single Cylindrical Hole (SCH) arrangement. In order to reduce the CRVP effects, tremendous efforts from the past researchers have been made including the introduction of the Double Cylindrical Hole …
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An Experimental Investigation of Spanwise Vortices Interacting with Solid and Free Surfaces
… main cases were examined: the interaction of a vortex pair propagating towards a solid boundary, the interaction of spanwise vortices in a turbulent boundary layer, and finally the interaction of spanwise vortices with a flat-plate wake and a free liquid surface. These problems hold significance …
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Oblique Shock Wave Effects on Impulsively Accelerated Heavy Gas Column
… vortices. The streamwise extent of the vortex pair in the centerline plane (cross-section) images of the column is proportional to the square root of A divided by the square root of M, regardless of oblique shock angle for theta < 20. A heretofore unseen manifestation of Kelvin-Helmholtz …
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Performance analysis for lateral-line-inspired sensor arrays
… systems, namely shape identification and vortex tracking. The ability of pressure sensor arrays to emulate the ”touch at a distance” feature of the lateral line, corresponding to the latter’s capability of identifying the shape of objects remotely, is examined with respect to moving …
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Performance analysis for lateral-line-inspired sensor arrays
… systems, namely shape identification and vortex tracking. The ability of pressure sensor arrays to emulate the "touch at a distance" feature of the lateral line, corresponding to the latter's capability of identifying the shape of objects remotely, is examined with respect to moving …
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Computational Studies of Penetration and Mixing for Complex Jet Injectors to Aid in Design of Hypersonic Systems
… spreading rate and larger counter-rotating vortex pair with downstream distance over the non-reacting analysis. The mixing was not significantly altered by the addition of hydrogen-air reactions to the numerical equations. The numerical tools used are capable of reasonable accuracy in …
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