Flight mechanics model for spanwise lift and rolling moment distributions of a segmented active high-lift wing

Abstract

In this study the aerodynamics of wings using an active high-lift system are investigated. The target is the flight mechanical description of the spanwise forces and resulting moments and the influence of the active high-lift system to their distribution. The high-lift system is a blown flap system divided into six segments per wing. Each segment is assumed to be individually controlled, so the system shall be used for aircraft control and system failure management. This work presents a flight mechanical model for the simulation of flight dynamics, which has been derived from high-fidelity CFD results. An assessment of single segment blowing system failures will be presented including recommendations for compensation of either lift or rolling moment loss. For this investigation, the compensation is required to act at the same wing on which the failure appears.shall be proven. The results show that less performance investment in terms of pressurized air is necessary to compensate the rolling moment of a failing segment instead of its lift. However, large performance increases for the remaining wing segments occur for some of the failure cases.

Adaptive Nonlinear Flight Control of STOL-Aircraft Based on Incremental Nonlinear Dynamic Inversion

“…4. For an accurate simulation of partial failures of the active high-lift system a model of the spanwise lift distribution, depending on each compressor power setting was developed [32]. The individual compressor jet momentum coefficient C µ,comp is used whereas the mean of the individual coefficientC µ,comp = C µ .…”

Controllability of an aircraft with active high-lift system using a segmentwise controllable flap system

“…To assess the controllability of the aircraft using only the active high-lift system without any flap deflection variation, a model for the blowing influence on the local segmented aerodynamics of the wing is necessary. The model approach used in this paper was developed in a previous investigation [19]. To that end, the wing flaps are divided into the segmentation of Fig.…”

“…The segment 4 failure case was determined by CFD data and is the basis for modeling the remaining segment failure cases. Detailed information about the model development can be found in the previous studies [19]. Equation 9is determined by the ratio between the lift distribution at the global jet momentum coefficient C l;3 and the complete shutdown of the active high-lift system C l;1 and the ratio between the segment 4 failure case C l;5 and the complete shut down of the active high-lift system C l;1 .…”

“…Lift gradients and mapping factors[19] Controllability of an aircraft with active... each flap segment fli, by varying the jet momentum of a specific flap segment C l;fli . Thus, it is possible to change the lift distribution over the corresponding flap segment.…”

Un modelo para el control de cambio de forma de alas multifuncionales basado en interpolación G² de Hermite para curvas 3D

“…En general, los sistemas de control se basan en dos aspectos que, en algunos casos, pueden combinarse: i) modificar las propiedades del ala a lo largo de la envergadura; y ii) alterar la geometría de los perfiles alares. En algunos casos, el control de la distribución de cargas aerodinámicas se realiza a partir de la disposición a lo largo de la envergadura de superficies sustentadoras móviles que actúan independientemente, con los objetivos de mejorar la respuesta ante ráfagas [4], proporcionar mayor controlabilidad [5], [6] y/o suavizar los esfuerzos sobre la estructura [7], entre otros. Por su parte, el concepto de modificar la geometría o forma de una superficie alar no es moderna [8], sin embargo, hacerlo activamente para modificar la distribución de sustentación sin utilizar superficies articuladas representa un desafío.…”