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university of florida thesis or dissertation formatting template

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Figure 6-31 c<strong>or</strong>responds to the LE <strong>of</strong> the wing, and the right-hand side c<strong>or</strong>responds to the TE <strong>of</strong><br />

the wing. The top <strong>of</strong> the figure c<strong>or</strong>responds to the wingtip and the bottom to the root <strong>of</strong> the wing.<br />

The left-hand side <strong>of</strong> Figure 6-30 and Figure 6-32 c<strong>or</strong>responds to the same 2-D Lissajous plots<br />

seen in Figure 6-29 and Figure 6-31, respectively; and the right-hand side c<strong>or</strong>responds to the 3-D<br />

Lissajous plots with time being the third dimension. The red circle in all figures indicates the<br />

starting point <strong>of</strong> the cycle, and the black arrows indicate the direction <strong>of</strong> rotation.<br />

It can be seen in the lower left-hand p<strong>or</strong>tion <strong>of</strong> Figure 6-29 that there is a 0° (diagonal line<br />

downward to the left) phase shift region with counter-clockwise rotation. Progressing aft, the<br />

phase abruptly shifts to 180° (diagonal line downward to the right) with clockwise rotation. This<br />

shift is indicative <strong>of</strong> the pitch axis. Once in the 63% ch<strong>or</strong>d region, the Lissajous plots begin to<br />

open up, indicating the shock structure region. The plots then flip back to a 0° shift in the 78%<br />

ch<strong>or</strong>d region upon aft and inboard progression. However, in the outboard region, the phase<br />

remains at 180° and takes on a highly “odd” shape. This “odd” shape is also seen along the LE<br />

upon outboard movement from the 68% span section, and all along the tip <strong>of</strong> the wing. Any plot<br />

that is not a symmetric oval about an arbitrary axis is the result <strong>of</strong> a phase variation within 1<br />

cycle. The figure-eight plot is not a harmonic, as is n<strong>or</strong>mally associated with figure-eights, but<br />

the result <strong>of</strong> the phase changing sign. The phase changes from a lead to a lag, <strong>or</strong> vice-versa.<br />

Since the solution is “cyclically steady”, solutions at 0° are identical to 360° solutions, any time<br />

lag that shows up during a cycle has to be “made up” and that fall-behind and catch-up nature<br />

leads to the phase variation within a cycle that is shown here. The region beginning at the top<br />

(tip) in the 23-28% ch<strong>or</strong>d region and extending at the bottom (root) to the 43-48% ch<strong>or</strong>d-region,<br />

indicates a transition from clockwise to counter-clockwise rotation. Increased suction (increased<br />

lift) is seen with increased displacement (increase in AOA) in front <strong>of</strong> the pitch axis, as is<br />

88

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