Project Details
Projekt
Large Eddy Simulation of the interaction of wing wake and the horizontal tail plane under buffet conditions
Applicant
Professorin Dr.-Ing. Andrea D. Beck
Subject Area
Fluid Mechanics
Term
since 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 406435057
High-speed stall occurs at the upper edge of the flight envelope. It is characterized by a cyclic movement of the compression shock (so-called buffet phenomenon) and an associated flow separation. The resulting unsteady wing wake can hit the downstream horizontal tail plane and induce unwanted flow conditions and structural loads. This results in a complex, nonlinear chain of effects over a wide range of turbulent scales. The physical interpretation and numerical prediction of these coupled interactions remain challenging. In addition, during the measurements performed in Phase 1 on the XRF-1 configuration at ETW and on the fundamental experiment in the Trisonic wind tunnel at AIA, structural vibrations were observed, some of them significant. Their influence has not been considered in analysis and numerics so far. It is known that, depending on the frequency relation, a modulation of the buffet can occur. This additional influence increases the complexity of the chain of action buffet - wake - horizontal tail plane. Therefore, the goal of this research project is to contribute to the understanding of the interaction of wing wake and flow at the horizontal tail plane, taking into account the influence of structural vibrations. To this end, we first investigate the effects of vibrations on the buffet at the wing. We plan a structured progressive measurement and simulation campaign on the fundamental experiment, where TP5 is responsible for the simulative side. This strategy will allow us to clarify the mutual influences of geometric factors (sweep angle, span) and vibrations. Numerically, the individual effects (with and without vibrations) can be decoupled and considered separately. The basic question here is whether and how structural vibrations modulate buffet (especially in the 3D case) and whether or under which conditions a lock-in occurs. For this purpose, we make use of the in phase 1 established method of wall-modeled large-eddy simulation, extended to introduce the structural motions and deformations through a moving-grid formulation. The efficiency of these high-order methods allows for a significant increase in spanwise domain length over previously reported simulations. As a further sub-objective, we use this methodology to clarify the extent to which these vibrations modulate wake-tailplane interactions compared to Phase 1. For this purpose, we perform coupled AZDES-LES simulations of the overall interaction chain from wing to horizontal stabilizer including vibrations with our subproject partners. We characterize the influence of the vibrations on the overall scale.The overall project goal is thus to contribute to a detailed understanding of the basic physics of the modulation of buffet by structural vibrations and to transfer these findings to the buffet - wake - tailplane chain of action.
DFG Programme
Research Units
