TY - GEN A1 - Sharma, Sparsh A1 - Sarradj, Ennes T1 - Two-dimensional isotropic turbulent inflow conditions for vortex particle method T2 - Physical Review Fluids Y1 - 2019 U6 - https://doi.org/10.1103/PhysRevFluids.4.022701 SN - 2469-990X VL - 4 IS - 2 ER - TY - GEN A1 - Henke, Anna-Sophia A1 - Noack, Martin A1 - Geyer, Thomas A1 - Heinrich, Christoph Rocky A1 - Beirow, Bernd A1 - Sarradj, Ennes A1 - Kühhorn, Arnold T1 - Calculation of the Modal Behavior of Structured Sheet Metal T2 - International Journal of Lightweight Materials and Manufacture Y1 - 2019 U6 - https://doi.org/10.1016/j.ijlmm.2019.01.004 SN - 2588-8404 ER - TY - GEN A1 - Henke, Anna-Sophia A1 - Tepe, Ali A1 - Sarradj, Ennes T1 - Untersuchung des Abstrahlverhaltens strukturierter Bleche T2 - Fortschritte der Akustik - DAGA 2019, 45. Jahrestagung für Akustik, 18.-21. März 2019 in Rostock N2 - Stahlbleche sind auf Grund ihrer einfachen Fertigung und vielfältigen Anwendungsmöglichkeiten unentbehrlich in Bereichen wie dem Maschinen- und Fahrzeugbau oder der Architektur. Durch das Einbringen von Strukturen kann die Steifigkeit von Stahlplatten erhöht werden. So kann bei einem geringeren Materialeinsatz gleichbleibenden statischen Ansprüchen genügt werden. Eine derartige Umformung führt jedoch auch zu einem veränderten akustischen Verhalten von strukturierten Blechen gegenüber 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 Fensterprüfstand 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 für glatte und hexagonal strukturierte Bleche. Dabei wird im Besonderen auf den Einfluss der Strukturierung auf das Abstrahlmaß der Stahlbleche eingegangen. Y1 - 2019 UR - https://www.dega-akustik.de/publikationen/tagungsbaende/verzeichnisse/ ER - TY - GEN A1 - Merino-Martinez, Roberto A1 - Sijtsma, Pieter A1 - Snellen, Mirjam A1 - Ahlefeldt, Thomas A1 - Antoni, Jerome A1 - Bahr, Christopher A1 - Blacodon, Daniel A1 - Ernst, Daniel A1 - Finez, Arthur A1 - Funke, Stefan A1 - Geyer, Thomas A1 - Haxter, Stefan A1 - Herold, Gert A1 - Huang, Xun A1 - Humphreys, William A1 - Leclère, Quentin A1 - Malgoezar, Anwar A1 - Michel, Ulf A1 - Padois, Thomas A1 - Pereira, Antonio A1 - Picard, Christophe A1 - Sarradj, Ennes A1 - Siller, Henri A1 - Simons, Dick A1 - Spehr, Carsten T1 - A review of acoustic imaging methods using phased microphone arrays T2 - CEAS Aeronautical Journal N2 - 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. Y1 - 2019 U6 - https://doi.org/10.1007/s13272-019-00383-4 SN - 1869-5582 SN - 1869-5590 VL - 10 IS - 1 SP - 197 EP - 230 ER - TY - GEN A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Self Noise Reduction and Aerodynamics of Airfoils With Porous Trailing Edges T2 - Acoustics Y1 - 2019 U6 - https://doi.org/10.3390/acoustics1020022 SN - 2624-599X VL - 1 IS - 2 SP - 393 EP - 409 ER - TY - GEN A1 - Sharma, Sparsh A1 - Geyer, Thomas A1 - Sarradj, Ennes A1 - Schmidt, Heiko T1 - Numerical investigation of noise generation by rod-airfoil configuration using DES (SU2) and the FW-H analogy T2 - 25th AIAA/CEAS Aeroacoustics Conference 2019, Delft, The Netherlands, 20 - 24 May 2019, (AIAA 2019-2400) KW - airfoil noise KW - computational aeroacoustics KW - cylinder noise KW - detached eddy simulatio KW - ffowcs-williams hawkings KW - rod-airfoil Y1 - 2019 UR - https://arc.aiaa.org/doi/10.2514/6.2019-2400 U6 - https://doi.org/10.2514/6.2019-2400 SP - 1 EP - 17 ER - TY - CHAP A1 - Moreau, Danielle J. A1 - Geyer, Thomas A1 - Doolan, Con A1 - Sarradj, Ennes ED - Zhou, Yu ED - Kimura, Motoaki ED - Peng, Guoyi ED - Lucey, A. D. ED - Huang, Lixi T1 - Influence of Camber on Wall-Mounted Finite Airfoil Tonal Noise Generation T2 - Fluid-Structure-Sound Interactions and Control Proceedings of the 4th Symposium on Fluid-Structure-Sound Interactions and Control Y1 - 2019 SN - 978-981-10-7541-4 SN - 978-981-10-7542-1 U6 - https://doi.org/10.1007/978-981-10-7542-1_51 SP - 337 EP - 342 PB - Springer CY - Singapore ER - TY - GEN A1 - Geyer, Thomas A1 - Wasala, Sahan A1 - Sarradj, Ennes T1 - Experimental Study of Airfoil Leading Edge Combs for Turbulence Interaction Noise Reduction T2 - Acoustics Y1 - 2020 U6 - https://doi.org/10.3390/acoustics2020014 SN - 2624-599X VL - 2 IS - 2 SP - 207 EP - 223 ER - TY - GEN A1 - Sharma, Sparsh A1 - Sarradj, Ennes A1 - Schmidt, Heiko T1 - Stochastic modelling of leading-edge noise in time-domain using vortex particles T2 - Journal of Sound and Vibration Y1 - 2020 U6 - https://doi.org/10.1016/j.jsv.2020.115656 SN - 0022-460X VL - Vol. 488 ER - TY - GEN A1 - Ayton, Lorna A1 - Colbrook, Matthew A1 - Geyer, Thomas A1 - Chaitanya, Paruchuri A1 - Sarradj, Ennes T1 - Reducing aerofoil–turbulence interaction noise through chordwise-varying porosity T2 - Journal of Fluid Mechanics Y1 - 2020 U6 - https://doi.org/10.1017/jfm.2020.746 SN - 1469-7645 VL - 906 SP - A1 EP - A28 ER - TY - GEN A1 - Sharma, Sparsh A1 - Klein, Marten A1 - Schmidt, Heiko A1 - Sarradj, Ennes T1 - On a lower-order framework for jet noise prediction based on one-dimensional turbulence T2 - arXiv N2 - 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. KW - Ffowcs-Williams and Hawkings equation KW - jet noise KW - one-dimensional turbulence KW - turbulent mixing noise Y1 - 2020 UR - https://arxiv.org/abs/2010.11050 SP - 1 EP - 4 ER - TY - GEN A1 - Schneehagen, Erik W. A1 - Geyer, Thomas A1 - Sarradj, Ennes A1 - Moreau, Danielle J. T1 - Aeroacoustic noise reduction by application of end plates on wall‑mounted finite airfoils T2 - Experiments in Fluids Y1 - 2021 U6 - https://doi.org/10.1007/s00348-021-03204-9 SN - 0723-4864 SN - 1432-1114 VL - 62 IS - 5 ER - TY - GEN A1 - Geyer, Thomas A1 - Fritzsche, Christoph A1 - Sarradj, Ennes A1 - Wagner, Hermann T1 - Der leise Flug der Eule T2 - Akustik Journal Y1 - 2021 UR - https://www.dega-akustik.de/fileadmin/dega-akustik.de/publikationen/akustik-journal/21-02/akustik_journal_2021_02_online.pdf VL - 2021 IS - 2 SP - 9 EP - 17 ER - TY - GEN A1 - Ayton, Lorna A1 - Colbrook, Matthew A1 - Geyer, Thomas A1 - Chaitanya, Paruchuri A1 - Sarradj, Ennes T1 - Modelling chordwise-varying porosity to reduce aerofoil-turbulence interaction noise T2 - 27th AIAA/CEAS Aeroacoustics Conference 2021, Virtual Event, August 2 - 6 2021 Y1 - 2021 U6 - https://doi.org/10.2514/6.2021-2190 ER - TY - GEN A1 - Sharma, Sparsh A1 - Geyer, Thomas A1 - Sarradj, Ennes A1 - Schmidt, Heiko T1 - Experimental validation of a lower-order model for leading-edge noise based on vortex method T2 - 27th AIAA/CEAS Aeroacoustics Conference 2021, Virtual Event, August 2 - 6 2021 Y1 - 2021 U6 - https://doi.org/10.2514/6.2021-2250 ER - TY - GEN A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Aerodynamische Schallentstehung durchströmter Netze T2 - Fortschritte der Akustik - DAGA, 48. Jahrestagung für Akustik, 21. - 24. März 2022 Y1 - 2022 UR - https://pub.dega-akustik.de/DAGA_2022/data/articles/000133.pdf UR - https://www.daga2022.de/programm SP - 109 ER - TY - GEN A1 - Schneehagen, Erik W. A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Reduzierung des Eigengeräuschs von Tragflügeln durch Seitenplatten T2 - Fortschritte der Akustik - DAGA, 48. Jahrestagung für Akustik Y1 - 2022 UR - https://pub.dega-akustik.de/DAGA_2022/data/articles/000189.pdf ER - TY - GEN A1 - Schneehagen, Erik W. A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Influence of end plate placement on the reduction of airfoil tip vortex formation noise T2 - Acta Acustica Y1 - 2022 UR - https://acta-acustica.edpsciences.org/articles/aacus/full_html/2022/01/aacus220025/aacus220025.html U6 - https://doi.org/10.1051/aacus/2022053 SN - 2681-4617 VL - 6 SP - 1 EP - 14 ER - TY - GEN A1 - Neubauer, Moritz A1 - Genßler, Julia A1 - Radmann, Vincent A1 - Kohlenberg, Fleming A1 - Pohl, Michael A1 - Böhme, Kurt A1 - Knobloch, Karsten A1 - Sarradj, Ennes A1 - Höschler, Klaus A1 - Modler, Niels A1 - Enghardt, Lars T1 - Experimental and Numerical Investigation of Novel Acoustic Liners and Their Design for Aero-Engine Applications T2 - Aerospace N2 - 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. Y1 - 2023 U6 - https://doi.org/10.3390/aerospace10010005 SN - 2226-4310 VL - 10 IS - 1 ER - TY - GEN A1 - Geyer, Thomas A1 - Windisch, Thomas A1 - Fritzsche, Christoph A1 - Sarradj, Ennes T1 - Dataset on permeability of wings from owls and non-silently flying birds T2 - Data in Brief Y1 - 2024 U6 - https://doi.org/10.1016/j.dib.2023.109825 SN - 2352-3409 VL - 52 ER -