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Showing 1 to 11 of 11 for “"streamwise vortex"”.
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A study of streamwise vortex enhanced mixing in lobed mixer devices
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.
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Large eddy simulation of subsonic mixing layers
… temporal mixing layers, it is found that the streamwise vortex tubes play an important role in the transition process. The vortex interaction of the streamwise vortex tubes and undulated spanwise vortex structures proves to be the dominant mechanism in the development of three-dimensionality …
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Iced Airfoil Separation Bubble Measurements by Particle Image Velocimetry
… from the quasi-steady distribution of discrete, streamwise vortices which aided the turbulent entrainment of fluid from the recirculation region of the three-dimensional ice simulation separation bubble flowfield. These vortices were generated by a streamwise-vortex instability excited by …
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Numerical Investigation of the Wake of a Rectangular Wing
Wakes of lifting bodies contain vortex sheets that roll up into strong streamwise vortices. The long time behavior of such vortices depends on the turbulence in the wake and the stability characteristics of the vortices themselves. In the near wake of a rectangular wing the flow field consists of a …
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Experimental aero-acoustic assessment of swirling flows for drag applications
… pressure drag quietly by establishing a steady streamwise vortex. The simple concept of a so called swirl tube, a ducted set of stationary turning vanes, was implemented to experimentally assess the aerodynamic and aero-acoustic behavior of swirling flows. A modular design was chosen for the …
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Effects of blade damage on low pressure ratio fan windmill aerodynamics
… case of the rotor, the separated flow forms a streamwise vortex near the casing which reduces the work output and increases loss. The stator pressure side is fully separated, which dominates the stage loss. Axisymmetric fan tip damage shifts the work distribution down the span, which leads to a …
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Loss mechanisms in turbine tip clearance flows
… which takes the form of a strong embedded streamwise vortex (u=ux 1 in the vortex core), and the mainstream ow is found to be the main source of loss. Vortex line contraction, and consequent vortex core expansion, and also vortex breakdown, are identied as the two important mechanisms that …
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Octant Analysis of the Reynolds Stresses in the Three Dimensional Turbulent Boundary Layer of a Prolate Spheroid
… are more closely aligned with the quasi-streamwise vortex structures than free-stream coordinates. The octant analysis also reveals structural behavior consistent with the four mechanisms revealed by the direct numerical simulation of Sendstad and Moin (1992).
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The Effects of Shrouded Rotor Tip Leakage Flow on the Downstream Stator Aerodynamics in Turbines
… in the Whittle Laboratory. Measured contours of streamwise vorticity at the exit of the downstream stator identified two positive streamwise vortex structures. A computational study revealed that one vortex was caused by a large separation at the leading edge of the stator. It is demonstrated …
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Turbulent flowfield downstream of a perpendicular airfoil--vortex interaction
… downstream of an airfoil encountering an intense streamwise vortex. This type of perpendicular airfoil--vortex interaction commonly occurs in helicopter rotor flows. The experiments presented here thus provide useful information for the prediction of helicopter noise, particularly BWI noise. …
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The Aerodynamics of Low Sweep Delta Wings
… in the inboard part of the wing, an attached vortex can be sustained, reminiscent of delta-wing type of a tip vortex, but further in the outboard region 2-D stall dominated even at 13° AOA and total stall at 21° AOA. To explore the unsteady flow field and the effectiveness of leading-edge …