Assessment of body-freedom flutter for an unmanned aerial vehicle

Schäfer, Dominik; Vidy, Cyrille; Mack, Christoph J.; Arnold, Johannes

doi:10.1007/s13272-018-0353-9

Cited by 7 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, an aeroelastically sized model is given for further analysis of the MULDICON, as an example for flying wing configurations. With this aeroelastic model, a flutter investigation is performed in [44] concerning the body freedom flutter phenomenon like in a previous work regarding the predecessor DLR-F19 [45]. Moreover, the influence of high-fidelity aerodynamics on the sizing process using a CFD correction is investigated in [23].…”

Section: Discussionmentioning

confidence: 99%

Design and sizing of an aeroelastic composite model for a flying wing configuration with maneuver, gust, and landing loads

2020

View full text Add to dashboard Cite

The paper addresses the application of a parametric design process for a flying wing configuration. The multi-disciplinary configuration (MULDICON) is a generic unmanned combat air vehicle (UCAV) developed for research purposes, a further development of the DLR-F19 configuration, which was used for research activities in the scope of the DLR project Mephisto and its predecessors FaUSST and UCAV2010. For the MULDICON, the DLR parametric design process MONA is applied. Special emphasis is placed on the structural modeling with composite material where each layer is modeled and analyzed. Various failure criteria are compared to define suitable constraints for the optimization of the load carrying structure. In contrast to optimize the thickness of composites with global allowable strains, such strategy allows for a detailed analysis of every layer. The number of constraints due to the set-up of every ply is substantially increased compared to the strain allowables but the structural optimization is still applicable. The detailed structural and mass models represent the global stiffness and structural dynamic characteristics of the aircraft. For the loads analysis part of the design process, 9 different mass configurations with a total of 306 maneuvering load cases as well as 336 1-cos gust load cases are taken into account. Furthermore, a new simplified landing impact simulation is introduced to consider 12 landing load cases. All load cases are defined according to regulations like CS-25. Such number of load cases is necessary to cover a sufficient number of flight conditions. For the selection of the design loads for the structural optimization, the essential loads are analyzed for a subset of locations. Together with a parametrized optimization model, the structural optimization is conducted. The result is a weight-optimized structural model for the MULDICON. This entire model allows for the investigation of physics-based effects already at an early stage of the design process.

show abstract

Section: Discussionmentioning

confidence: 99%

Design and sizing of an aeroelastic composite model for a flying wing configuration with maneuver, gust, and landing loads

2020

View full text Add to dashboard Cite

show abstract

“…For example, fixed-wing aircraft are limited in their performance (required take-off/landing distance, velocity, fuel efficiency, ceiling, range, climb rate, and controllability speeds). Aircraft also have limitations regarding gross weight, maximum horizontal velocity, minimum velocity for fixed-wing (due to stall threat), and maximum descent velocity due to flatter hazard [22]. In practice, it means that geometrically the shortest path cannot be feasible at all for most fixed-wing aircraft if the trajectory planner proposes too high pitch angles, for example.…”

Section: Aircraft Performance and Maneuverabilitymentioning

confidence: 99%

A Critical Review of Information Provision for U-Space Traffic Autonomous Guidance

Panov,

Ul Haq

2024

Aerospace

View full text Add to dashboard Cite

This paper identifies and classifies the essential constraints that must be addressed to allow U-space traffic autonomous guidance. Based on an extensive analysis of the state of the art in robotic guidance, physics of flight, flight safety, communication and navigation, uncrewed aircraft missions, artificial intelligence (AI), social expectations in Europe on drones, etc., we analyzed the existing constraints and the information needs that are of essential importance to address the identified constraints. We compared the identified information needs with the last edition of the U-space Concept of Operations and identified critical gaps between the needs and proposed services. A high-level methodology to identify, measure, and close the gaps is proposed.

show abstract

“…Issues due to coupled flight dynamics and aeroelasticity have been recently observed on several UAVs [13,8,14], featuring layouts resembling the Flying Wings. However, there is another aircraft architecture that seems to be inherently prone to this coupling: the Box Wing [15].…”

Section: Introductionmentioning

confidence: 99%

Studies on Coupled Flight Dynamics and Aeroelasticity of a Prandtlplane Configuration

Bombardieri¹,

Cavallaro²,

Castellanos³

et al. 2021

Preprint

View full text Add to dashboard Cite

The PrandtlPlane aircraft has been recently considered as a possible candidate to foster the ambition of a greener aviation. Despite the relevant amount of research carried out in the last years, several aspects of this novel configuration still need further insight to pave the way to future applications. Among them, the coupled flight-dynamic and aeroelastic response still deserves further investigation, and will be addressed in this work by means of a dedicated in-house framework. For the evaluation of the aerodynamic forces, an enhanced Doublet Lattice Method, able to take into account terms typically neglected by classic formulations, is integrated in the framework.First, flight-dynamic aspects are considered, showing how effects of interaction between Short Period or Dutch Roll with elastic modes remarkably deteriorate the flying qualities. Then, focus is on the aeroelastic stability of the aircraft. As observed also in previous literature efforts on this configuration, flutter onset is considerably different when considering the aircraft being free in the air or fixed in space. Thanks to the adopted formulation it is shown how, for this PrandtlPlane, the aerodynamic coupling of elastic and rigid modes has a beneficial effect on flutter onset. However, the different modal properties, consequence of the diverse boundary conditions, when switching from fixed-in-space to free-flying aircraft, also play a relevant role in determining the occurrence of flutter. Whereas for the longitudinal case both effects are synergistic, contributing to increase flutter speed, for the lateral-directional case the variation in modal properties has a detrimental and dominating effect, leading to a flutter speed well within the flight envelope.Finally, the work discusses the contributions of the additional terms modeled by the enhanced Doublet Lattice Method, showing how they induce a considerable effect when modeling the flight dynamics of the flexible aircraft.

show abstract

Assessment of body-freedom flutter for an unmanned aerial vehicle

Cited by 7 publications

References 10 publications

Design and sizing of an aeroelastic composite model for a flying wing configuration with maneuver, gust, and landing loads

Design and sizing of an aeroelastic composite model for a flying wing configuration with maneuver, gust, and landing loads

A Critical Review of Information Provision for U-Space Traffic Autonomous Guidance

Studies on Coupled Flight Dynamics and Aeroelasticity of a Prandtlplane Configuration

Contact Info

Product

Resources

About