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The wing of an active high lift aircraft configuration with an UHBR engine is structurally sized. The FEA details droop nose and flaps and uses loads from 3D CFD RANS simulations for the fully stressed design. The sizing yields a comparable skin thickness distribution compared to a similar wing configuration with a Turboprop engine. The differences in mass result mainly from the relatively high UHBR engine weight and the higher sweep angle. Furthermore the steady aeroelastic equilibrium is computed with a partitioned approach for the landing configuration at optimal circulation control. Flow separation is initiated at the end of the unprotected leading edge, propagating to the outboard main wing and aileron. The effect of the wing elasticity onto the aerodynamics is negligible due to the high stiffness of the UHBR configuration.

Approaching a traffic light regulated intersection or road segment represents a challenge in the context of fully or partially automated vehicles. The current state of an upcoming traffic light needs to be detected reliably and the resulting vehicle approach behavior can therefore only be based on the current state of the traffic light. While camera-based detection systems for traffic lights only allow for capturing the current state of the traffic light, its remaining duration is usually unknown, just as it is for manually operated vehicles. Vehicle-to-everything (V2X) communications enables vehicles to also receive information about the remaining duration of the current state directly from the infrastructure and to therefore optimize the approach behavior to arrive within the current or upcoming green windows. While the majority of related contributions aim at computing a green light optimal advisory speed or propose a computationally expensive optimization technique, this contribution introduces a lightweight and scalable methodology enabling the generation of an optimized approach behavior for connected (partially) automated vehicles. The introduced concept of a convex solution space targets a low computational overhead and still allows for adapting the vehicle speed to surrounding traffic participants.

Extended configurations of a short take-off and landing aircraft under investigation at the Coordinated Research Centre SFB 880 include a morphing droop nose and a tractor propeller engine. The short take-off and landing capabilities are achieved by circulation control via a high velocity jet over the flap leading edges utilizing the Coandǎ effect. The effect of the engine integration in combination with the blown flaps on the wing sizing, aerodynamic performance, and static wing deformation are of large interest. High-detail structural wing models are sized with a fully stressed approach using a partitioned fluid–structure interaction process. The aerodynamic part is covered by highly detailed computational fluid simulations. The effect of modeling the engine on the global and local aerodynamics for different levels of circulation control has a large impact. In addition, a change in flow separation behavior due to the engine effects is observed. The wing mass is only slightly increased by the detailed engine aerodynamics and the separation behavior changes slightly for the elastic wing. These findings show that the modeling of the engine will lead to a different stall behavior and allow for a higher lift, while the influence on the wing structure and aeroelasticity are very small.

The aeroelastic behavior of the wing of a 100-passenger aircraft under investigation in the Coordinated Research Center SFB 880 is studied. A compressed air jet upstream of the high-lift devices called the Coanda jet enables boundary layer control with delayed flow separation and consequently high lift. Aeroelastic instabilities caused by boundary layer control systems are critical to the aircraft performance. The understanding of cause and effect of these instabilities is of great importance. For analyses, a multilevel approach is pursued using full-scale three-dimensional models and reduced-order models. Both model types use fluid-structure interaction techniques. The full-scale models are used to generate a sized wing structure with realistic mass and stiffness distributions using computational fluid dynamics loads of cruise and landing configuration load cases. A reduced-order model is derived by modal reduction for computationally efficient investigations of multiple flight states. To study local aer...

A nonlinear, transient surrogate model is constructed to replace the computational fluid dynamics solver within the aeroelastic analysis of a detailed aircraft wing with variable fuel tank levels during cruise flight. This surrogate model allows high-fidelity analyses at a fraction of the original computational cost with satisfactory accuracy. During the model construction a parameter reduction via proper orthogonal decomposition is combined with a radial basis function artificial network for system identification and nonlinear effects. Transient forced motion computational fluid dynamics analyses based solely on the structural dynamic behavior of the detailed wing model are used as training inputs. To assess the accuracy of the approach the reduced-order model results are compared with high-fidelity full-scale aeroelastic computations. A small local reduction in accuracy can be seen for highly nonlinear effects like dynamic shock movements. However, variations in tank fill level or angle of attack show sufficient agreement of the model with the full-scale analyses. An interpolation of an intermediary angle of attack shows higher errors due to large changes in aerodynamic phenomena between the sample points.

Summary A shear-flexible isogeometric Reissner–Mindlin shell formulation using non-uniform rational B-splines basis functions is introduced, which is used for the demonstration of a coupling approach for multiple non-conforming patches. The six degrees of freedom formulation uses the exact surface normal vectors and curvature. The shell formulation is implemented in an isogeometric analysis framework for computation of structures composed of multiple geometric entities. To enable local model refinement as well as non-matching domains coupling, a conservative multi-patch approach using Lagrange multipliers for structured non-uniform rational B-splines patches is presented. Here, an additional border frame mesh is used to couple geometries during structural analyses. This frame interface approach avoids the problem of excessive constraints when multiple patches are coupled at one point. First, the shell formulation is verified with several reference cases. Then the influence of the frame interface discretization and frame penalty stiffness on the smoothness of the results is investigated. The effects of the perturbed Lagrangian method in combination with the frame interface approach is shown. In addition, results of models with T-joint interface connections and perpendicular stiffener patches are presented. Copyright © 2016 John Wiley & Sons, Ltd.

Preliminary design tools are essential during aircraft design to make conclusions about an aircraft’s performance. Generally this process employs methods of low and medium fidelity to create comparatively fast results for a high number of parameter variations. High-fidelity methods are needed to verify theses results and to consider components in more detail. A 100 PAX commercial aircraft with short take-off and landing capabilities of 800 m with circulation controlled high-lift devices is under investigation at the Collaborative Research Centre SFB 880. In this paper, a global wing analysis with a high detail model is conducted and the results are compared with results attained with a preliminary aircraft design tool. Several detailed designs for the air feed system integration are proposed and examined regarding weight and stiffness characteristics on a representative high-lift device section model. Fluid–structure coupling is employed during all analyses to transfer aerodynamic loads and structural displacements. The aeroelastic impact of the slot stiffness on the Coandǎ effect during landing is then quantified. The attained aerodynamic performance results and structural characteristics of each configuration are compared and the advantages are discussed.