Investigation of Shock Motion in Transonic Flow Using an Oscillating, Straked, Delta Wing

Abstract

A computational analysis was performed on a straked, delta wing undergoing pitch motion in order to investigate the influence of shock-induced, trailing-edge separation (SITES) on simulated limit-cycle oscillations (LCO). The research presented herein describes an aeroelastic analysis of a wing oscillating in pitch using Euler-based aerodynamics with boundary-layer coupling (BLC). Results indicate that oscillatory shock movement occurs in response to the pitching motion of the wing, both with and without BLC. However, the BLC solution predicted more significant shock movement, and the inviscid solution predicted more aggressive shocks located further aft on the wing. Increasing the amplitude of the pitch oscillations resulted in a greater range of shock motion than lower amplitude cases, but variation of oscillation frequencies tested did not show any noteworthy differences. These findings support the theory that oscillatory shock movement associated with SITES can occur during certain cases of transonic LCO. In addition, based on the results from pure pitch motion of the wing and on the flow solver used, shock motion can occur without a boundary-layer model, although the modeling of viscous effects does affect the range of shock motion.