@misc{GeyerKampsSarradjetal., author = {Geyer, Thomas and Kamps, Laura and Sarradj, Ennes and Br{\"u}cker, Christoph}, title = {Vortex Shedding and Modal Behavior of a Circular Cylinder Equipped with Flexible Flaps}, series = {Acta Acustica united with Acustica}, volume = {105}, journal = {Acta Acustica united with Acustica}, number = {1}, issn = {1610-1928}, doi = {10.3813/aaa.919301}, pages = {210 -- 219}, language = {en} } @misc{SharmaSarradj, author = {Sharma, Sparsh and Sarradj, Ennes}, title = {Two-dimensional isotropic turbulent inflow conditions for vortex particle method}, series = {Physical Review Fluids}, volume = {4}, journal = {Physical Review Fluids}, number = {2}, issn = {2469-990X}, doi = {10.1103/PhysRevFluids.4.022701}, pages = {11}, language = {en} } @misc{HenkeNoackGeyeretal., author = {Henke, Anna-Sophia and Noack, Martin and Geyer, Thomas and Heinrich, Christoph Rocky and Beirow, Bernd and Sarradj, Ennes and K{\"u}hhorn, Arnold}, title = {Calculation of the Modal Behavior of Structured Sheet Metal}, series = {International Journal of Lightweight Materials and Manufacture}, journal = {International Journal of Lightweight Materials and Manufacture}, issn = {2588-8404}, doi = {10.1016/j.ijlmm.2019.01.004}, pages = {13}, language = {en} } @misc{HenkeTepeSarradj, author = {Henke, Anna-Sophia and Tepe, Ali and Sarradj, Ennes}, title = {Untersuchung des Abstrahlverhaltens strukturierter Bleche}, series = {Fortschritte der Akustik - DAGA 2019, 45. Jahrestagung f{\"u}r Akustik, 18.-21. M{\"a}rz 2019 in Rostock}, journal = {Fortschritte der Akustik - DAGA 2019, 45. Jahrestagung f{\"u}r Akustik, 18.-21. M{\"a}rz 2019 in Rostock}, abstract = {Stahlbleche sind auf Grund ihrer einfachen Fertigung und vielf{\"a}ltigen Anwendungsm{\"o}glichkeiten unentbehrlich in Bereichen wie dem Maschinen- und Fahrzeugbau oder der Architektur. Durch das Einbringen von Strukturen kann die Steifigkeit von Stahlplatten erh{\"o}ht werden. So kann bei einem geringeren Materialeinsatz gleichbleibenden statischen Anspr{\"u}chen gen{\"u}gt werden. Eine derartige Umformung f{\"u}hrt jedoch auch zu einem ver{\"a}nderten akustischen Verhalten von strukturierten Blechen gegen{\"u}ber glatten Blechen. Im Rahmen einer Studie an der BTU Cottbus-Senftenberg zum akustischen Verhalten hexagonal wabenstrukturierter Stahlbleche wurde das Abstrahlverhalten dieser Bleche untersucht. Dazu wurden im Fensterpr{\"u}fstand der TU Berlin experimentell die abgestrahlte Schallleistung sowie die Schwingschnelle von mit einem Shaker angeregten Blechen ermittelt. Aus den so gewonnenen Daten wurde das Abstrahlmaß berechnet. Der Beitrag zeigt das Verfahren und veranschaulicht die Ergebnisse vergleichend f{\"u}r glatte und hexagonal strukturierte Bleche. Dabei wird im Besonderen auf den Einfluss der Strukturierung auf das Abstrahlmaß der Stahlbleche eingegangen.}, language = {de} } @misc{MerinoMartinezSijtsmaSnellenetal., author = {Merino-Martinez, Roberto and Sijtsma, Pieter and Snellen, Mirjam and Ahlefeldt, Thomas and Antoni, Jerome and Bahr, Christopher and Blacodon, Daniel and Ernst, Daniel and Finez, Arthur and Funke, Stefan and Geyer, Thomas and Haxter, Stefan and Herold, Gert and Huang, Xun and Humphreys, William and Lecl{\`e}re, Quentin and Malgoezar, Anwar and Michel, Ulf and Padois, Thomas and Pereira, Antonio and Picard, Christophe and Sarradj, Ennes and Siller, Henri and Simons, Dick and Spehr, Carsten}, title = {A review of acoustic imaging methods using phased microphone arrays}, series = {CEAS Aeronautical Journal}, volume = {10}, journal = {CEAS Aeronautical Journal}, number = {1}, issn = {1869-5582}, doi = {10.1007/s13272-019-00383-4}, pages = {197 -- 230}, abstract = {Phased microphone arrays have become a well-established tool for performing aeroacoustic measurements in wind tunnels (both open-jet and closed-section), flying aircraft, and engine test beds. This paper provides a review of the most well-known and state-of-the-art acoustic imaging methods and recommendations on when to use them. Several exemplary results showing the performance of most methods in aeroacoustic applications are included. This manuscript provides a general introduction to aeroacoustic measurements for non-experienced microphone-array users as well as a broad overview for general aeroacoustic experts.}, language = {en} } @misc{GeyerSarradj, author = {Geyer, Thomas and Sarradj, Ennes}, title = {Self Noise Reduction and Aerodynamics of Airfoils With Porous Trailing Edges}, series = {Acoustics}, volume = {1}, journal = {Acoustics}, number = {2}, issn = {2624-599X}, doi = {10.3390/acoustics1020022}, pages = {393 -- 409}, language = {en} } @misc{SharmaGeyerSarradjetal., author = {Sharma, Sparsh and Geyer, Thomas and Sarradj, Ennes and Schmidt, Heiko}, title = {Numerical investigation of noise generation by rod-airfoil configuration using DES (SU2) and the FW-H analogy}, series = {25th AIAA/CEAS Aeroacoustics Conference 2019, Delft, The Netherlands, 20 - 24 May 2019, (AIAA 2019-2400)}, journal = {25th AIAA/CEAS Aeroacoustics Conference 2019, Delft, The Netherlands, 20 - 24 May 2019, (AIAA 2019-2400)}, doi = {10.2514/6.2019-2400}, pages = {1 -- 17}, language = {en} } @incollection{MoreauGeyerDoolanetal., author = {Moreau, Danielle J. and Geyer, Thomas and Doolan, Con and Sarradj, Ennes}, title = {Influence of Camber on Wall-Mounted Finite Airfoil Tonal Noise Generation}, series = {Fluid-Structure-Sound Interactions and Control Proceedings of the 4th Symposium on Fluid-Structure-Sound Interactions and Control}, booktitle = {Fluid-Structure-Sound Interactions and Control Proceedings of the 4th Symposium on Fluid-Structure-Sound Interactions and Control}, editor = {Zhou, Yu and Kimura, Motoaki and Peng, Guoyi and Lucey, A. D. and Huang, Lixi}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7541-4}, doi = {10.1007/978-981-10-7542-1_51}, pages = {337 -- 342}, language = {en} } @misc{GeyerWasalaSarradj, author = {Geyer, Thomas and Wasala, Sahan and Sarradj, Ennes}, title = {Experimental Study of Airfoil Leading Edge Combs for Turbulence Interaction Noise Reduction}, series = {Acoustics}, volume = {2}, journal = {Acoustics}, number = {2}, issn = {2624-599X}, doi = {10.3390/acoustics2020014}, pages = {207 -- 223}, language = {en} } @misc{SharmaSarradjSchmidt, author = {Sharma, Sparsh and Sarradj, Ennes and Schmidt, Heiko}, title = {Stochastic modelling of leading-edge noise in time-domain using vortex particles}, series = {Journal of Sound and Vibration}, volume = {Vol. 488}, journal = {Journal of Sound and Vibration}, issn = {0022-460X}, doi = {10.1016/j.jsv.2020.115656}, pages = {30}, language = {en} } @misc{AytonColbrookGeyeretal., author = {Ayton, Lorna and Colbrook, Matthew and Geyer, Thomas and Chaitanya, Paruchuri and Sarradj, Ennes}, title = {Reducing aerofoil-turbulence interaction noise through chordwise-varying porosity}, series = {Journal of Fluid Mechanics}, volume = {906}, journal = {Journal of Fluid Mechanics}, issn = {1469-7645}, doi = {10.1017/jfm.2020.746}, pages = {A1 -- A28}, language = {en} } @misc{SharmaKleinSchmidtetal., author = {Sharma, Sparsh and Klein, Marten and Schmidt, Heiko and Sarradj, Ennes}, title = {On a lower-order framework for jet noise prediction based on one-dimensional turbulence}, series = {arXiv}, journal = {arXiv}, pages = {1 -- 4}, abstract = {Noise prediction requires the resolution of relevant acoustic sources on all scales of a turbulent flow. High-resolution direct numerical and large-eddy simulation would be ideal but both are usually too costly despite developments in high performance computing. Lower-order modeling approaches are therefore of general interest. A crucial but standing problem for accurate predictive modeling is the estimation of missing noise from the modeled scales. In this paper we address this problem by presenting a novel lower-order framework that couples the one-dimensional turbulence model to the Ffowcs-Williams and Hawkings approach for prediction of the far-field noise of a subsonic turbulent round jet.}, language = {en} } @misc{SchneehagenGeyerSarradjetal., author = {Schneehagen, Erik W. and Geyer, Thomas and Sarradj, Ennes and Moreau, Danielle J.}, title = {Aeroacoustic noise reduction by application of end plates on wall‑mounted finite airfoils}, series = {Experiments in Fluids}, volume = {62}, journal = {Experiments in Fluids}, number = {5}, issn = {0723-4864}, doi = {10.1007/s00348-021-03204-9}, language = {en} } @misc{GeyerFritzscheSarradjetal., author = {Geyer, Thomas and Fritzsche, Christoph and Sarradj, Ennes and Wagner, Hermann}, title = {Der leise Flug der Eule}, series = {Akustik Journal}, volume = {2021}, journal = {Akustik Journal}, number = {2}, pages = {9 -- 17}, language = {de} } @misc{AytonColbrookGeyeretal., author = {Ayton, Lorna and Colbrook, Matthew and Geyer, Thomas and Chaitanya, Paruchuri and Sarradj, Ennes}, title = {Modelling chordwise-varying porosity to reduce aerofoil-turbulence interaction noise}, series = {27th AIAA/CEAS Aeroacoustics Conference 2021, Virtual Event, August 2 - 6 2021}, journal = {27th AIAA/CEAS Aeroacoustics Conference 2021, Virtual Event, August 2 - 6 2021}, doi = {10.2514/6.2021-2190}, language = {en} } @misc{SharmaGeyerSarradjetal., author = {Sharma, Sparsh and Geyer, Thomas and Sarradj, Ennes and Schmidt, Heiko}, title = {Experimental validation of a lower-order model for leading-edge noise based on vortex method}, series = {27th AIAA/CEAS Aeroacoustics Conference 2021, Virtual Event, August 2 - 6 2021}, journal = {27th AIAA/CEAS Aeroacoustics Conference 2021, Virtual Event, August 2 - 6 2021}, doi = {10.2514/6.2021-2250}, language = {en} } @misc{GeyerSarradj, author = {Geyer, Thomas and Sarradj, Ennes}, title = {Aerodynamische Schallentstehung durchstr{\"o}mter Netze}, series = {Fortschritte der Akustik - DAGA, 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022}, journal = {Fortschritte der Akustik - DAGA, 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022}, pages = {109}, language = {de} } @misc{SchneehagenGeyerSarradj, author = {Schneehagen, Erik W. and Geyer, Thomas and Sarradj, Ennes}, title = {Reduzierung des Eigenger{\"a}uschs von Tragfl{\"u}geln durch Seitenplatten}, series = {Fortschritte der Akustik - DAGA, 48. Jahrestagung f{\"u}r Akustik}, journal = {Fortschritte der Akustik - DAGA, 48. Jahrestagung f{\"u}r Akustik}, language = {de} } @misc{SchneehagenGeyerSarradj, author = {Schneehagen, Erik W. and Geyer, Thomas and Sarradj, Ennes}, title = {Influence of end plate placement on the reduction of airfoil tip vortex formation noise}, series = {Acta Acustica}, volume = {6}, journal = {Acta Acustica}, issn = {2681-4617}, doi = {10.1051/aacus/2022053}, pages = {1 -- 14}, language = {en} } @misc{NeubauerGensslerRadmannetal., author = {Neubauer, Moritz and Genßler, Julia and Radmann, Vincent and Kohlenberg, Fleming and Pohl, Michael and B{\"o}hme, Kurt and Knobloch, Karsten and Sarradj, Ennes and H{\"o}schler, Klaus and Modler, Niels and Enghardt, Lars}, title = {Experimental and Numerical Investigation of Novel Acoustic Liners and Their Design for Aero-Engine Applications}, series = {Aerospace}, volume = {10}, journal = {Aerospace}, number = {1}, issn = {2226-4310}, doi = {10.3390/aerospace10010005}, abstract = {This paper presents a combined experimental and numerical investigation on a novel liner concept for enhanced low-frequency and broadband acoustic attenuation. In particular, two different realizations, derived from conventional Helmholtz resonators (HR) and plate resonators (PR) are investigated, which both deploy flexible materials with material inherent damping. In this context, a comprehensive experimental investigation was carried out focusing the identification and evaluation of various geometric parameters and material properties on the acoustics dissipation and related properties of various materials in a simplified setup of a single Helmholtz resonator with flexible walls (FHR concept). Furthermore, a parameter study based on analytical models was performed for both liner concepts, taking into account material as well as geometric parameters and their effects on transmission loss. In addition, design concepts that enable cylindrical or otherwise curved liner structures and the corresponding manufacturing technologies are presented, while considering essential structural features such as drainage. With respect to the potential application in jet engines, a structural-mechanical analysis considering the relevant load cases to compare and discuss the mechanical performance of a classical HR and the FHR concept liner is presented. Finally, both concepts are evaluated and possible challenges and potentials for further implementation are described.}, language = {en} } @misc{GeyerWindischFritzscheetal., author = {Geyer, Thomas and Windisch, Thomas and Fritzsche, Christoph and Sarradj, Ennes}, title = {Dataset on permeability of wings from owls and non-silently flying birds}, series = {Data in Brief}, volume = {52}, journal = {Data in Brief}, issn = {2352-3409}, doi = {10.1016/j.dib.2023.109825}, language = {en} } @misc{GeyerWindischFritzscheetal., author = {Geyer, Thomas and Windisch, Thomas and Fritzsche, Christoph and Sarradj, Ennes}, title = {Dataset on airflow resistance of wings from owls and non-silently flying birds}, doi = {10.17632/ndcndtstcf.1}, language = {en} }