Active Gust Alleviation on a High Aspect Ratio Wing Based on High Fidelity CFD Simulations

Abstract

When it comes to reducing the mass of the wing and realizing aerodynamically more efficient wing shapes, active gust load alleviation systems will be one of the central topics in the design of future aircraft. Such a system is investigated on a twin-engine wide-body configuration with an ultra-high efficiency, high aspect ratio wing and a high bypass ratio engine modeled as a flow through nacelle. Segmented leading and trailing edge flaps (TEF) form the active gust load alleviation system. Here, the leading edge flaps (LEF) are applied for torsion control and the TEF for lift control respectively bending control. The gust interaction is studied using a vertical 1 − cos gust based on rigid URANS CFD simulations. A gust wavelength study is performed to determine the load dominating gust. Based on that, a wavelength is defined which is considered for the design of the load alleviation system. 2D studies with gust are performed to determine the 3D flap deflection angles. Within the 3D gust simulations, the leading edge flaps and the trailing edge flaps are dynamically deflected in order to analyze their effect on an high aspect ratio wing. For the evaluation of the load alleviation potential, the 2D data are transferred to the twin-engine wide-body configuration, where on the one hand the dynamic trailing edge flap and on the other hand a combined dynamic deflection of trailing and leading edge flaps are investigated. It is shown using a dynamic deflection of the trailing edge flaps, the wing bending moment is reduced by 97.4% percent.