university of florida thesis or dissertation formatting template

(CFD) analyses in order to capture the nonlinearities in the LCO mechanism not captured by
traditional flutter analysis.
For this dissertation, an 8Hz mode is chosen, as this is representative of a typical straight-
and-level LCO mechanism. Additionally, based on actual flight test accelerometer data, ±0.5° of
displacement is chosen as a reasonable wingtip displacement.
Grids and Boundary Conditions
The grids used for this research consist of viscous, full-scale models of the F-16. Half-span
grids are required for the pitch cases, full-span for the roll cases, and different grids are required
for each configuration change. The boundary conditions are symmetry (half-span only), adiabatic
solid wall for the surface of the aircraft and the engine duct, and modified Riemann invariants for
the far-field boundaries. The exact Riemann solver is replaced with an inviscid flux function that
alleviates the inherent shortcomings of Riemann methods, namely the “slowly-moving shock”
and “carbuncle” problems, while retaining their inherent advantages, most notably the exact
capture of stationary contact surfaces. 106
Far-field boundary conditions should be applied at outer boundaries. The outer boundaries
need to be far enough away so they do not influence the area of interest of the simulation.
Typically, the boundaries should be six to eight characteristic body lengths away from the
configuration of interest. Far-field boundary condition types are used for regions of inflow and
outflow.
Solid wall boundary conditions should be applied where there is no flow through
boundaries. There are two broad categories of solid walls: slip and no-slip. A slip wall enforces
the tangency condition, and a no-slip wall enforces no relative velocity at the surface. The
adiabatic no-slip method applies a zero relative velocity at the boundary. Pressure and density
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