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experimental study of vortex response during cutting by a blade or cylinder

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Date Issued:
1993
Summary:
An experimental study of the vortex response to interaction with and cutting by a thin flat plate or circular cylinders of various diameters has been performed. The direction of motion of the flat plate (or circular cylinder) is normal to the vortex axis in the experiments. The vortex is generated by withdraw of fluid at an orifice at the bottom of an "inner cylinder" immersed in a rectangular tank, and the flow field is visualized with both water soluble and immiscible dyes. In the experiments with circular cylinders, the bending of the vortex is compared to computational predictions from [15], and the mechanism of subsequent breakup of the vortex as it gets closer to the cylinder is studied. The vortex is observed to bend farther without breakup for larger forward speeds of the circular cylinder. Very little bending is observed when the vortex interacts with the flat plate, except for angles of attack exceeding the stall limit Following cutting of the vortex by the flat plate or circular cylinder, a vortex shock is observed to form and propagate up the vortex axis. No vortex shock is observed on the opposite side of the blade. The various forms of these vortex shocks have been photographed, and they appear very similar to travelling vortex breakdowns. The propagation speed of the shocks is compared to an analytical solution for instantaneous vortex cutting by a flat plate of zero thickness.
Title: An experimental study of vortex response during cutting by a blade or cylinder.
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Name(s): Krishnamoorthy, Srikanth.
Florida Atlantic University, Degree grantor
Marshall, Jeffrey S., Thesis advisor
College of Engineering and Computer Science
Department of Ocean and Mechanical Engineering
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Issuance: monographic
Date Issued: 1993
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 74 p.
Language(s): English
Summary: An experimental study of the vortex response to interaction with and cutting by a thin flat plate or circular cylinders of various diameters has been performed. The direction of motion of the flat plate (or circular cylinder) is normal to the vortex axis in the experiments. The vortex is generated by withdraw of fluid at an orifice at the bottom of an "inner cylinder" immersed in a rectangular tank, and the flow field is visualized with both water soluble and immiscible dyes. In the experiments with circular cylinders, the bending of the vortex is compared to computational predictions from [15], and the mechanism of subsequent breakup of the vortex as it gets closer to the cylinder is studied. The vortex is observed to bend farther without breakup for larger forward speeds of the circular cylinder. Very little bending is observed when the vortex interacts with the flat plate, except for angles of attack exceeding the stall limit Following cutting of the vortex by the flat plate or circular cylinder, a vortex shock is observed to form and propagate up the vortex axis. No vortex shock is observed on the opposite side of the blade. The various forms of these vortex shocks have been photographed, and they appear very similar to travelling vortex breakdowns. The propagation speed of the shocks is compared to an analytical solution for instantaneous vortex cutting by a flat plate of zero thickness.
Identifier: 14977 (digitool), FADT14977 (IID), fau:11756 (fedora)
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): College of Engineering and Computer Science
Thesis (M.S.)--Florida Atlantic University, 1993.
Subject(s): Vortex-motion
Blades--Noise
Cylinders
Rotors (Helicopters)
Helicopters--Noise
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fcla/dt/14977
Sublocation: Digital Library
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.