@inproceedings{MertensBraunerBaieretal.2022,
  author    = {Mertens, Alexander and Brauner, Philipp and Baier, Ralph and Brillowski, Florian and Dammers, Hannah and van Dyck, Marc and Kong, Iris and K{\"o}nigs, Peter and Kordtomeikel, Frauke and Liehner, Gian Luca and P{\"u}tz, Sebastian and Rodermann, Niklas and Schaar, Anne Kathrin and Steuer-Dankert, Linda and Vervier, Luisa and Wlecke, Shari and Gries, Thomas and Leicht-Scholten, Carmen and Nagel, Saskia K. and Piller, Frank T. and Schuh, G{\"u}nther and Ziefle, Martina and Nitsch, Verena},
  title     = {Modelling Human Factors in Cyber Physical Production Systems by the Integration of Human Digital Shadows},
  series = {Modellierung 2022 Satellite Events},
  booktitle = {Modellierung 2022 Satellite Events},
  editor    = {Michael, Judith and Pfeiffer, J{\´e}r{\^o}me and Wortmann, Andreas},
  publisher = {GI Gesellschaft f{\"u}r Informatik},
  address   = {Bonn},
  doi       = {10.18420/modellierung2022ws-018},
  pages     = {147 -- 149},
  year      = {2022},
  abstract  = {The future of industrial manufacturing and production will increasingly manifest in the form of cyber-physical production systems. Here, Digital Shadows will act as mediators between the physical and digital world to model and operationalize the interactions and relationships between different entities in production systems. Until now, the associated concepts have been primarily pursued and implemented from a technocentric perspective, in which human actors play a subordinate role, if they are considered at all. This paper outlines an anthropocentric approach that explicitly considers the characteristics, behavior, and traits and states of human actors in socio-technical production systems. For this purpose, we discuss the potentials and the expected challenges and threats of creating and using Human Digital Shadows in production.},
  language  = {en}
}
@article{HartungDondetiCastleford2007,
  author    = {Hartung, Frank and Dondeti, L. and Castleford, F.},
  title     = {Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST LTKM/STKM Transport / Dondeti, L. ; Castleford, D. ; Hartung, F.},
  pages     = {1 -- 7},
  year      = {2007},
  language  = {en}
}
@article{HartungSchiederKampmannetal.2006,
  author    = {Hartung, Frank and Schieder, Andreas and Kampmann, Markus and Vorwerk, Marc},
  title     = {Network Supported Media Delivery in Ambient Networks (Netzwerkunterst{\"u}tzte Medienverteilung) / Schieder, Andreas ; Kampmann, Markus ; Hartung, Frank ; Vorwerk, Marc ; Rembarz, Ren{\´e}},
  series = {it - Information Technology . 48 (2006), H. 5},
  journal   = {it - Information Technology . 48 (2006), H. 5},
  isbn      = {1611-2776},
  pages     = {264 -- 273},
  year      = {2006},
  language  = {en}
}
@book{EngelnMuellgesUhlig1996,
  author    = {Engeln-M{\"u}llges, Gisela and Uhlig, Frank},
  title     = {Numeric Algorithms with Fortran},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {3-540-60529-0},
  pages     = {XXII, 602 S. : Ill., graph. Darst. + 1 CD-ROM},
  year      = {1996},
  language  = {en}
}
@book{EngelnMuellgesUhlig1996,
  author    = {Engeln-M{\"u}llges, Gisela and Uhlig, Frank},
  title     = {Numerical algorithms with C},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {3-540-60530-0},
  pages     = {XXII, 596 S. : graph. Darst. + 1 CD-ROM},
  year      = {1996},
  language  = {en}
}
@inproceedings{MoehrenBergmannJanseretal.2023,
  author    = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten},
  title     = {On the determination of harmonic propeller loads},
  series = {AIAA SCITECH 2023 Forum},
  booktitle = {AIAA SCITECH 2023 Forum},
  publisher = {AIAA},
  doi       = {10.2514/6.2023-2404},
  pages     = {12 Seiten},
  year      = {2023},
  abstract  = {Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures.},
  language  = {en}
}
@article{MoehrenBergmannJanseretal.2023,
  author    = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten},
  title     = {On the influence of elasticity on propeller performance: a parametric study},
  series = {CEAS Aeronautical Journal},
  volume    = {14},
  journal   = {CEAS Aeronautical Journal},
  publisher = {Springer Nature},
  address   = {Berlin},
  issn      = {1869-5590 (Online)},
  doi       = {10.1007/s13272-023-00649-y},
  pages     = {311 -- 323},
  year      = {2023},
  abstract  = {The aerodynamic performance of propellers strongly depends on their geometry and, consequently, on aeroelastic deformations. Knowledge of the extent of the impact is crucial for overall aircraft performance. An integrated simulation environment for steady aeroelastic propeller simulations is presented. The simulation environment is applied to determine the impact of elastic deformations on the aerodynamic propeller performance. The aerodynamic module includes a blade element momentum approach to calculate aerodynamic loads. The structural module is based on finite beam elements, according to Timoshenko theory, including moderate deflections. Several fixed-pitch propellers with thin-walled cross sections made of both isotropic and non-isotropic materials are investigated. The essential parameters are varied: diameter, disc loading, sweep, material, rotational, and flight velocity. The relative change of thrust between rigid and elastic blades quantifies the impact of propeller elasticity. Swept propellers of large diameters or low disc loadings can decrease the thrust significantly. High flight velocities and low material stiffness amplify this tendency. Performance calculations without consideration of propeller elasticity can lead to decreased efficiency. To avoid cost- and time-intense redesigns, propeller elasticity should be considered for swept planforms and low disc loadings.},
  language  = {en}
}
@article{BergmannMoehrenBraunetal.2023,
  author    = {Bergmann, Ole and M{\"o}hren, Felix and Braun, Carsten and Janser, Frank},
  title     = {On the influence of elasticity on swept propeller noise},
  series = {AIAA SCITECH 2023 Forum},
  journal   = {AIAA SCITECH 2023 Forum},
  publisher = {AIAA},
  address   = {Reston, Va.},
  doi       = {10.2514/6.2023-0210},
  year      = {2023},
  abstract  = {High aerodynamic efficiency requires propellers with high aspect ratios, while propeller sweep potentially reduces noise. Propeller sweep and high aspect ratios increase elasticity and coupling of structural mechanics and aerodynamics, affecting the propeller performance and noise. Therefore, this paper analyzes the influence of elasticity on forward-swept, backward-swept, and unswept propellers in hover conditions. A reduced-order blade element momentum approach is coupled with a one-dimensional Timoshenko beam theory and Farassat's formulation 1A. The results of the aeroelastic simulation are used as input for the aeroacoustic calculation. The analysis shows that elasticity influences noise radiation because thickness and loading noise respond differently to deformations. In the case of the backward-swept propeller, the location of the maximum sound pressure level shifts forward by 0.5 °, while in the case of the forward-swept propeller, it shifts backward by 0.5 °. Therefore, aeroacoustic optimization requires the consideration of propeller deformation.},
  language  = {en}
}
@inproceedings{NeuJanserKhatibietal.2015,
  author    = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.},
  title     = {Operational modal analysis of a cantilever in a wind tunnel using optical fiber bragg grating sensors},
  series = {6th International Operational Modal Analysis Conference. IOMAC´15. 2015 May 12-14 Gijon - Spain},
  booktitle = {6th International Operational Modal Analysis Conference. IOMAC´15. 2015 May 12-14 Gijon - Spain},
  doi       = {10.13140/RG.2.1.3753.0324},
  pages     = {10 S.},
  year      = {2015},
  language  = {en}
}
@article{NeuJanserKhatibietal.2016,
  author    = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Braun, Carsten and Orifici, Adrian C.},
  title     = {Operational Modal Analysis of a wing excited by transonic flow},
  series = {Aerospace Science and Technology},
  volume    = {49},
  journal   = {Aerospace Science and Technology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1270-9638},
  doi       = {10.1016/j.ast.2015.11.032},
  pages     = {73 -- 79},
  year      = {2016},
  abstract  = {Operational Modal Analysis (OMA) is a promising candidate for flutter testing and Structural Health Monitoring (SHM) of aircraft wings that are passively excited by wind loads. However, no studies have been published where OMA is tested in transonic flows, which is the dominant condition for large civil aircraft and is characterized by complex and unique aerodynamic phenomena. We use data from the HIRENASD large-scale wind tunnel experiment to automatically extract modal parameters from an ambiently excited wing operated in the transonic regime using two OMA methods: Stochastic Subspace Identification (SSI) and Frequency Domain Decomposition (FDD). The system response is evaluated based on accelerometer measurements. The excitation is investigated from surface pressure measurements. The forcing function is shown to be non-white, non-stationary and contaminated by narrow-banded transonic disturbances. All these properties violate fundamental OMA assumptions about the forcing function. Despite this, all physical modes in the investigated frequency range were successfully identified, and in addition transonic pressure waves were identified as physical modes as well. The SSI method showed superior identification capabilities for the investigated case. The investigation shows that complex transonic flows can interfere with OMA. This can make existing approaches for modal tracking unsuitable for their application to aircraft wings operated in the transonic flight regime. Approaches to separate the true physical modes from the transonic disturbances are discussed.},
  language  = {en}
}