Dylan N. Hope

Date of Award

3-22-2018

Document Type

Thesis

Degree Name

Master of Science in Aeronautical Engineering

Department

Department of Aeronautics and Astronautics

First Advisor

Donald Kunz, PhD.

Abstract

In support of the Air Force Office of Scientific Research, this project sought to identify the significance of nonlinear aerodynamic phenomena in regards to LCO of a straked delta wing design. Previous works include unsteady Navier-Stokes aeroelastic analysis of various wing designs and flight test of F-16 transonic LCO with interest focused on oscillatory SITES behavior. The research presented within this investigation further expanded the understanding of unsteady aerodynamics by performing aeroelastic analysis of a wing oscillated in pitch with an Euler-based, boundary layer coupled numerical method (ZEUS). The wing was tested for a multitude of LCO parameters such as median AoA, oscillation amplitude, oscillation frequency, Mach number, and the type of numerical solver used. Computed pressure data sets were analyzed along the wing's surface at 4 chordwise stations along the wing's span. Results indicate that oscillatory shock migration occurs in response to the pitching motion of the wing. ZEUS has the capability to run either a fully inviscid solution or a boundary layer coupled solution (BLC). While the use of both methods found shock migration to occur, the BLC solution predicted more significant shock migration. The inviscid solution predicted more aggressive shocks located further aft on the wing than the BLC solution. In regards to oscillation amplitude, increasing the amplitude resulted in a greater range of shock migration than lower amplitude cases. Both oscillation frequencies tested did not show any noteworthy differences. The aforementioned findings support the theory that potential oscillatory shock migration can occur during certain cases of transonic LCO. In addition, it was concluded that based on the flow solver used (ZEUS), shock movement during LCO is not purely a function of viscosity (SITES), although the modeling of viscous effects does affect the range of shock migration.

AFIT Designator

AFIT-ENY-MS-18-M-264

DTIC Accession Number

AD1056580

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