university of florida thesis or dissertation formatting template
university of florida thesis or dissertation formatting template
university of florida thesis or dissertation formatting template
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
occurring at harmonics, and assumes a periodic response. The wavelet plot in C) reveals non-<br />
periodic features that are not seen in the FFT. The blue region at time=0.21 sec c<strong>or</strong>responds to<br />
the wide peak region and consists <strong>of</strong> a range <strong>of</strong> frequencies, whereas the green region at time=0.3<br />
sec c<strong>or</strong>responds to the narrow trough region and consists <strong>of</strong> one, clear frequency.<br />
Flow Visualization<br />
Wing-Only Pitch Oscillations<br />
In <strong>or</strong>der to examine the effect <strong>of</strong> the fuselage, the next step in the FSR approach is to<br />
perf<strong>or</strong>m f<strong>or</strong>ced, rigid body pitch oscillation f<strong>or</strong> a refined F-16 wing-only Wing1 with LE edge<br />
antenna and tip launcher. Motion is prescribed f<strong>or</strong> 8Hz±0.5° rigid-body pitch oscillation at the<br />
same flow conditions (αi=1.34°, Mach=0.9, altitude=5k feet) with the same turbulence model<br />
(DDES-SARC) as the tip-launcher aircraft Grid8 f<strong>or</strong> direct comparison.<br />
Figure 6-49 and Figure 6-50 illustrate images visualizing the flow computed on the left<br />
wing (looking aft-f<strong>or</strong>ward) at the upward stroke (between pitch angles <strong>of</strong> 135° and 180°) <strong>of</strong> the<br />
8Hz ±0.5° sinusoidal pitching cycle. These images depict the instantaneous Mach = 1 boundary<br />
(Figure 6-49) and v<strong>or</strong>ticity magnitude=50 (Figure 6-50) iso-surfaces with the aircraft surface<br />
col<strong>or</strong>ed by pressure. The AOA is shown as a function <strong>of</strong> time in the upper half in each set <strong>of</strong><br />
images. Additionally, BL159 is indicated along the LE <strong>of</strong> each <strong>of</strong> the images f<strong>or</strong> reference<br />
purposes. The left set <strong>of</strong> images in display the Wing1 wing-only case results f<strong>or</strong> the upper<br />
surface in A) and lower surface in B), and the Grid8 aircraft comparisons are presented on the<br />
right f<strong>or</strong> the upper surface in C) and lower surface in D).<br />
In Figure 6-49 A), it is seen that the Mach=1 boundary iso-surface is much larger f<strong>or</strong> the<br />
wing-only case than f<strong>or</strong> the aircraft case in C). The small secondary shock aft <strong>of</strong> the primary<br />
shock near the tip launcher due to the tip launcher notch is still seen but it is smaller than it is<br />
with the aircraft in C). The most interesting difference between the wing-only and aircraft cases<br />
100
Change language