Large Eddy Simulation of the Interaction between the Wing Wake and Horizontal Tail Plane under Buffet Conditions

At the boundaries of the flight envelope, the aerodynamics and loads of the horizontal tail plane are influenced by the unsteady behavior and turbulence of the wing wake, which constitutes an important aspect of aircraft certification. The present work investigates this interaction under high-speed stall conditions. The research focuses on a generic tandem configuration consisting of an OAT15A airfoil as the main wing and a NACA 64A-110 airfoil as the horizontal tail plane. Under high-speed stall conditions, the main wing exhibits a self-sustaining periodic shock oscillation, commonly referred to as buffet. Using this configuration, the impact of the buffet on the boundary layer of the horizontal tail plane is investigated by analyzing the pressure fluctuations and the instantaneous and statistical properties of the boundary layer.

To investigate these phenomena, a toolchain for efficient, scale-resolving zonal large eddy simulation is developed that encompasses wall-modeled large eddy simulation capabilities. Using this simulation approach, it is shown that large-scale structures in the main wing's turbulent wake substantially impact the boundary layer dynamics on the horizontal tail plane, causing discernible alterations of the boundary layer statistics and thus in lift and drag. Furthermore, it is observed that pressure fluctuations originating from the buffet oscillation itself are orders of magnitude smaller than the wake-induced fluctuations. Additionally, the simulation of the tandem configuration underlines that scale-resolving simulations remain indispensable for gaining insights into the nuanced interactions within the boundary layer as the wake and boundary layer interact. As a result, the effect of structures of different sizes on the boundary layer can be efficiently quantified using the developed toolchain.