TY - GEN A1 - Geyer, Thomas A1 - Kamps, Laura A1 - Sarradj, Ennes A1 - Brücker, Christoph T1 - Passive Control of the Vortex Shedding Noise of a Cylinder at Low Reynolds Numbers Using Flexible Flaps T2 - 23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3015) Y1 - 2017 UR - https://arc.aiaa.org/doi/abs/10.2514/6.2017-3015 SN - 978-1-62410-504-3 PB - AIAA CY - Reston, Va ER - TY - GEN A1 - Moreau, Danielle J. A1 - Geyer, Thomas A1 - Doolan, Con A1 - Sarradj, Ennes T1 - Camber Effects on the Tonal Noise and Flow Characteristics of a Wall-mounted Finite Airfoil T2 - 23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3172) Y1 - 2017 UR - https://arc.aiaa.org/doi/abs/10.2514/6.2017-3172 SN - 978-1-62410-504-3 PB - AIAA CY - Reston, Va ER - TY - GEN A1 - Kamps, Laura A1 - Brücker, Christoph A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Airfoil Self Noise Reduction at Low Reynolds Numbers Using a Passive Flexible Trailing Edge T2 - 23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3496) Y1 - 2017 UR - https://arc.aiaa.org/doi/abs/10.2514/6.2017-3496 SN - 978-1-62410-504-3 PB - AIAA CY - Reston, Va ER - TY - GEN A1 - Sarradj, Ennes A1 - Herold, Gert A1 - Sijtsma, Pieter A1 - Merino-Martinez, Roberto A1 - Geyer, Thomas A1 - Bahr, Christopher A1 - Porteous, Ric A1 - Moreau, Danielle J. A1 - Doolan, Con T1 - A Microphone Array Method Benchmarking Exercise using Synthesized Input Data T2 - 23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3719) Y1 - 2017 UR - https://arc.aiaa.org/doi/pdfplus/10.2514/6.2017-3719 SN - 978-1-62410-504-3 PB - AIAA CY - Reston, Va ER - TY - GEN A1 - Herold, Gert A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Comparison of Inverse Deconvolution Algorithms for High-resolution Aeroacoustic Source Characterization T2 - 23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-4177) Y1 - 2017 UR - https://arc.aiaa.org/doi/abs/10.2514/6.2017-4177 SN - 978-1-62410-504-3 PB - AIAA CY - Reston, Va ER - TY - GEN A1 - Geyer, Thomas A1 - Claus, Vanessa A1 - Hall, Philipp A1 - Sarradj, Ennes T1 - Silent Owl Flight: The Effect of the Leading Edge Comb T2 - International Journal of Aeroacoustics Y1 - 2017 SN - 2048-4003 VL - 16 IS - 3 SP - 115 EP - 134 ER - TY - GEN A1 - Geyer, Thomas A1 - Schulz, Adrian A1 - Thürmer, Konrad A1 - Sarradj, Ennes A1 - Stapel, Jennifer T1 - Schallemission wasserwirtschaftlicher Anlagen T2 - Lärmbekämpfung Y1 - 2017 SN - 1436-4999 IS - 3 SP - 99 EP - 103 ER - TY - CHAP A1 - Moreau, Danielle J. A1 - Geyer, Thomas A1 - Doolan, Con A1 - Sarradj, Ennes T1 - Influence of Camber on Wall-Mounted Finite Airfoil Tonal Noise Generation T2 - 4th Symposium on Fluid-Structure-Sound Interactions and Control, Tokio, 2017 Y1 - 2018 SN - 978-981-10-7542-1 SN - 978-981-10-7541-4 SP - 337 EP - 342 PB - Springer CY - Singapore ER - TY - GEN A1 - Geyer, Thomas A1 - Poppe, Willi A1 - Sarradj, Ennes T1 - Measurement of flow noise generation and pressure loss of nets and screens T2 - Applied Acoustics Y1 - 2018 U6 - https://doi.org/10.1016/j.apacoust.2018.01.008 SN - 0003-682X VL - 134 SP - 69 EP - 74 ER - TY - GEN A1 - Henke, Anna-Sophia A1 - Sarradj, Ennes A1 - Langhof, Carsten T1 - Driving-point mobility and sound insulation of structured sheet metal T2 - Applied Acoustics Y1 - 2018 SN - 0003-682X VL - 136 SP - 113 EP - 122 ER - TY - GEN A1 - Hoeltgen, Laurent A1 - Breuß, Michael A1 - Herold, Gert A1 - Sarradj, Ennes T1 - Sparse ℓ1 regularisation of matrix valued models for acoustic source characterisation T2 - Optimization and Engineering N2 - We present a strategy for the recovery of a sparse solution of a common problem in acoustic engineering, which is the reconstruction of sound source levels and locations applying microphone array measurements. The considered task bears similarities to the basis pursuit formalism but also relies on additional model assumptions that are challenging from a mathematical point of view. Our approach reformulates the original task as a convex optimisation model. The sought solution shall be a matrix with a certain desired structure. We enforce this structure through additional constraints. By combining popular splitting algorithms and matrix differential theory in a novel framework we obtain a numerically efficient strategy. Besides a thorough theoretical consideration we also provide an experimental setup that certifies the usability of our strategy. Finally, we also address practical issues, such as the handling of inaccuracies in the measurement and corruption of the given data. We provide a post processing step that is capable of yielding an almost perfect solution in such circumstances. KW - Convex optimisation KW - Sparse recovery KW - Split Bregman KW - Microphone array KW - Matrix differentiation KW - Acoustic source characterisation Y1 - 2018 U6 - https://doi.org/10.1007/s11081-017-9357-2 SN - 1389-4420 SN - 1573-2924 VL - 19 IS - 1 SP - 39 EP - 70 ER - TY - CHAP A1 - Jekosch, Simon A1 - Sarradj, Ennes A1 - Herold, Gert A1 - Geyer, Thomas T1 - Comparison of different solvers for general inverse beamforming algorithms for highresolution aeroacoustic source characterization T2 - 7th Berlin Beamforming Conference, BeBeC Y1 - 2018 UR - http://www.bebec.eu/Downloads/BeBeC2018/Papers/BeBeC-2018-D08.pdf ER - TY - CHAP A1 - Kisler, Roman A1 - Materne, Daniel A1 - Geyer, Thomas A1 - Sarradj, Ennes T1 - Modularer Versuchsstand zur Charakterisierung von Plattenschalldämpfern T2 - Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung für Akustik, 19.-22. März 2018 in München Y1 - 2018 UR - https://www-docs.b-tu.de/fg-akustik/public/veroeffentlichungen/kisler_versuchsstand_daga2018.pdf SP - 441 EP - 444 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - CHAP A1 - Schneehagen, Erik W. A1 - Sarradj, Ennes A1 - Geyer, Thomas T1 - Numerische Simulation des Strömungsgeräusches eines wandbündigen Zylinders T2 - Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung für Akustik, 19.-22. März 2018 in München Y1 - 2018 UR - https://www-docs.b-tu.de/fg-akustik/public/veroeffentlichungen/schneehagen_zylinder_daga2018.pdf SP - 1001 EP - 1004 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - CHAP A1 - Sarradj, Ennes A1 - Herold, Gert A1 - Geyer, Thomas T1 - Vergleich verschiedener Mikrofonarray-Verfahren anhand synthetischer Daten T2 - Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung für Akustik, 19.-22. März 2018 in München Y1 - 2018 UR - https://www-docs.b-tu.de/fg-akustik/public/veroeffentlichungen/sarradj_mikrofonarrayverfahren_daga2018.pdf SP - 1391 EP - 1394 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - CHAP A1 - Geyer, Thomas A1 - Moreau, Danielle J. A1 - Sarradj, Ennes A1 - Doolan, Con T1 - Zur Schallentstehung an dreidimensionalen wandgebundenen Tragflügelprofilen T2 - Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung für Akustik, 19.-22. März 2018 in München Y1 - 2018 UR - https://www-docs.b-tu.de/fg-akustik/public/veroeffentlichungen/geyer_wandgebundeneprofile_daga2018.pdf SP - 1587 EP - 1590 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - CHAP A1 - Sharma, Sparsh A1 - Sarradj, Ennes A1 - Schmidt, Heiko T1 - Low-Fidelity Stochastic Approach for Airfoil-Turbulence Interaction Noise T2 - Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung für Akustik, 19.-22. März 2018 in München Y1 - 2018 UR - https://www-docs.b-tu.de/fg-akustik/public/veroeffentlichungen/sharma_stochastic_daga2018.pdf SP - 1184 EP - 1187 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - CHAP A1 - Henke, Anna-Sophia A1 - Noack, Martin A1 - Sarradj, Ennes T1 - Untersuchung des Modalverhaltens strukturierter Bleche T2 - Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung für Akustik, 19.-22. März 2018 in München Y1 - 2018 UR - https://www-docs.b-tu.de/fg-akustik/public/veroeffentlichungen/henke_modalverhalten_daga2018.pdf SP - 469 EP - 472 PB - Deutsche Gesellschaft für Akustik CY - Berlin ER - TY - GEN A1 - Kisler, Roman A1 - Sarradj, Ennes T1 - Plate Silencers for Broadband Low Frequency Sound Attenuation T2 - Acta Acustica united with Acustica N2 - An efficiency improvement for the implementation of a semi-analytical model of plate silencers in ducts is presented in this work. It is shown that a high approximation quality can be maintained even if the computation effort is reduced significantly. Thus, preliminary designs of plate silencers for specific purposes can be conducted with little effort. In addition, the accelerated implementation is utilized to perform an extensive parameter variation in order to find a best case configuration of silen properties and corresponding design rules. The results of these studies show that a tuning of plate and geometry parameters allow for substantial increases in a silencer's attenuation performance. Y1 - 2018 SN - 1610-1928 SN - 1861-9959 VL - 104 IS - 3 SP - 521 EP - 527 ER - TY - GEN A1 - Moreau, Danielle J. A1 - Geyer, Thomas A1 - Doolan, Con A1 - Sarradj, Ennes T1 - Surface curvature effects on the tonal noise of a wall-mounted finite airfoil T2 - The Journal of the Acoustical Society of America N2 - This paper is concerned with the influence of camber on the noise of a wall-mounted finite airfoil with natural boundary layer transition. Tonal noise measurements taken in an aeroacoustic wind tunnel are presented for airfoils with aspect ratio of 2, NACAxx12 profile and camber between 0 and 6% at 40% chord. The results show camber is an important parameter that determines the operating conditions for which acoustic tone generation occurs and the number and intensity of the tones produced. Airfoils with 0%–2% camber have an acoustic signature that is dominated by a high amplitude primary tone, whereas the spectra of airfoils with higher camber of 4%–6% feature a more pronounced side tone structure. Tonal noise production does not collapse with lift coefficient, demonstrating that the local flow conditions influence the noise source. Tonal noise production is explained in terms of changes to mean flow topology, namely the location of flow separation, which is linked to tonal noise generation. Scaling of airfoil tonal noise is found to vary with angle of attack and pressure gradient. Empirical scaling laws for the primary tone frequency dependence on velocity are also derived for the cambered airfoils. Y1 - 2018 U6 - https://doi.org/10.1121/1.5040981 SN - 1520-8524 VL - 143 IS - 6 SP - 3460 EP - 3473 ER - TY - GEN A1 - Geyer, Thomas A1 - Moreau, Danielle J. A1 - Giesler, Jens A1 - Hall, Philipp A1 - Sarradj, Ennes A1 - Doolan, Con T1 - Measurement of the noise generated by wall-mounted airfoils of different thickness T2 - 24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3796) Y1 - 2018 UR - https://arc.aiaa.org/doi/abs/10.2514/6.2018-3796 SN - 978-1-62410-560-9 PB - AIAA CY - Reston, Va ER -