Model
Digital Document
Publisher
Florida Atlantic University
Description
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.
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.
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