Self-induced wing rock of slender delta wings

TLDR

Wing rock at low speed is a known issue for slender delta wings in combat aircraft, but the underlying aerodynamic mechanisms remain poorly understood. This study investigates the aerodynamic factors responsible for low‑speed wing rock in slender delta wings. The authors performed static‑force tests and dynamic wind‑tunnel experiments—including forced oscillation, rotary, and free‑to‑roll tests—on an 80° leading‑edge sweep flat‑plate delta wing, complemented by tuft‑pattern and helium‑bubble flow visualizations. Results reveal the aerodynamic mechanisms driving wing rock and highlight challenges in mathematically modeling the associated aerodynamics and motions.

Abstract

As part of a research program aimed at exploring basic mechanisms that cause wing rock in combat aircraft, an investigation was conducted to study the aerodynamic factors which cause the low-speed wing rock exhibited by slender delta wings. A flat-plate delta wing with 80 deg leading-edge sweep was subjected to conventional static-force tests and dynamic wind-tunnel experiments which included forced-oscillation, rotary, and free-to-roll tests. In addition, visualization of the flow phenomena involved was obtained by observing tuft patterns and using a helium-bubble technique. This paper summarizes the results of this study. Fundamental information is presented on the aerodynamic mechanisms that cause the wing rock and the problem of mathematically modeling the aerodynamics and motions is discussed.