@misc{HeroldZengerSarradj, author = {Herold, Gert and Zenger, Florian and Sarradj, Ennes}, title = {Analyzing Noise Components on Skewed Fans with a Virtual Rotating Microphone Array : AIAA paper 2016-2761}, series = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016}, journal = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016}, publisher = {Curran Associates}, address = {Red Hook, NY}, isbn = {978-1-5108-2672-4}, language = {en} } @inproceedings{HeroldSarradj, author = {Herold, Gert and Sarradj, Ennes}, title = {Frequency Domain Deconvolution for Rotating Sources on an Axial Fan}, series = {BeBeC, 6th Berlin Beamforming Conference, February 29 - March 1, 2016, proceedings}, booktitle = {BeBeC, 6th Berlin Beamforming Conference, February 29 - March 1, 2016, proceedings}, publisher = {Berlin}, address = {Gesellschaft zur F{\"o}rderung angewandter Informatik}, pages = {8}, language = {en} } @misc{CaldasGrecoHeroldetal., author = {Caldas, Luciano and Greco, Paolo and Herold, Gert and Baccal{\´a}, Luiz}, title = {In-Duct Rotating Beamforming and Mode Detection of Fan Noise Sources : AIAA paper 2016-3034}, series = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016, vol. 7}, journal = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016, vol. 7}, publisher = {Curran Associates}, address = {Red Hook, NY}, isbn = {978-1-5108-2672-4}, pages = {5140 -- 5155}, language = {en} } @misc{ZengerHeroldBeckeretal., author = {Zenger, Florian and Herold, Gert and Becker, Stefan and Sarradj, Ennes}, title = {Sound source localization on an axial fan at different operating points}, series = {Experiments in Fluids}, volume = {57}, journal = {Experiments in Fluids}, issn = {0723-4864}, doi = {10.1007/s00348-016-2223-8}, pages = {136}, language = {en} } @misc{ZengerHeroldBecker, author = {Zenger, Florian and Herold, Gert and Becker, Stefan}, title = {Acoustic Characterization of Forward- and Backward-Skewed Axial Fans under Increased Inflow Turbulence : AIAA paper 2016-2943}, series = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016, vol. 4}, journal = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016, vol. 4}, publisher = {Curran Associates}, address = {Red Hook, NY}, isbn = {978-1-5108-2672-4}, pages = {3682 -- 3694}, language = {en} } @inproceedings{HeroldSarradj, author = {Herold, Gert and Sarradj, Ennes}, title = {Acoular - Open-Source-Software zur Anwendung von Mikrofonarrayverfahren}, series = {Fortschritte der Akustik, DAGA 2016, Aachen, 14.-17. M{\"a}rz 2016, 42. Jahrestagung f{\"u}r Akustik}, booktitle = {Fortschritte der Akustik, DAGA 2016, Aachen, 14.-17. M{\"a}rz 2016, 42. Jahrestagung f{\"u}r Akustik}, publisher = {DAGA}, address = {Berlin}, isbn = {978-3-939296-10-2}, language = {de} } @misc{SarradjHerold, author = {Sarradj, Ennes and Herold, Gert}, title = {A Python framework for microphone array data processing}, series = {Applied Acoustics}, volume = {116}, journal = {Applied Acoustics}, issn = {0003-682X}, doi = {10.1016/j.apacoust.2016.09.015}, pages = {50 -- 58}, language = {en} } @misc{HeroldGeyerMarkusetal., author = {Herold, Gert and Geyer, Thomas and Markus, Philipp and Sarradj, Ennes}, title = {Simultaneous Sound Power Measurement of Engine Components}, series = {SAE International Journal of Passenger Cars - Mechanical Systems}, volume = {9}, journal = {SAE International Journal of Passenger Cars - Mechanical Systems}, number = {3}, issn = {1946-3995}, doi = {10.4271/2016-01-1774}, pages = {974 -- 979}, language = {en} } @inproceedings{HallHeroldGeyeretal., author = {Hall, Philipp and Herold, Gert and Geyer, Thomas and Sarradj, Ennes}, title = {Vergleich verschiedener Methoden zur Schallleistungsbestimmung von Maschinenkomponenten}, series = {Fortschritte der Akustik, 43. Deutsche Jahrestagung f{\"u}r Akus tik, 6.-9. M{\"a}rz 2017 in Kiel}, booktitle = {Fortschritte der Akustik, 43. Deutsche Jahrestagung f{\"u}r Akus tik, 6.-9. M{\"a}rz 2017 in Kiel}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V. (DEGA)}, address = {Berlin}, isbn = {978-3-939296-12-6}, pages = {564 -- 567}, language = {de} } @misc{SarradjHeroldSijtsmaetal., author = {Sarradj, Ennes and Herold, Gert and Sijtsma, Pieter and Merino-Martinez, Roberto and Geyer, Thomas and Bahr, Christopher and Porteous, Ric and Moreau, Danielle J. and Doolan, Con}, title = {A Microphone Array Method Benchmarking Exercise using Synthesized Input Data}, series = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3719)}, journal = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3719)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-504-3}, language = {en} } @misc{HeroldGeyerSarradj, author = {Herold, Gert and Geyer, Thomas and Sarradj, Ennes}, title = {Comparison of Inverse Deconvolution Algorithms for High-resolution Aeroacoustic Source Characterization}, series = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-4177)}, journal = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-4177)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-504-3}, language = {en} } @misc{HoeltgenBreussHeroldetal., author = {Hoeltgen, Laurent and Breuß, Michael and Herold, Gert and Sarradj, Ennes}, title = {Sparse ℓ1 regularisation of matrix valued models for acoustic source characterisation}, series = {Optimization and Engineering}, volume = {19}, journal = {Optimization and Engineering}, number = {1}, issn = {1389-4420}, doi = {10.1007/s11081-017-9357-2}, pages = {39 -- 70}, abstract = {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.}, language = {en} } @inproceedings{JekoschSarradjHeroldetal., author = {Jekosch, Simon and Sarradj, Ennes and Herold, Gert and Geyer, Thomas}, title = {Comparison of different solvers for general inverse beamforming algorithms for highresolution aeroacoustic source characterization}, series = {7th Berlin Beamforming Conference, BeBeC}, booktitle = {7th Berlin Beamforming Conference, BeBeC}, pages = {10}, language = {en} } @inproceedings{SarradjHeroldGeyer, author = {Sarradj, Ennes and Herold, Gert and Geyer, Thomas}, title = {Vergleich verschiedener Mikrofonarray-Verfahren anhand synthetischer Daten}, series = {Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung f{\"u}r Akustik, 19.-22. M{\"a}rz 2018 in M{\"u}nchen}, booktitle = {Fortschritte der Akustik - DAGA 2018, 44. Jahrestagung f{\"u}r Akustik, 19.-22. M{\"a}rz 2018 in M{\"u}nchen}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik}, address = {Berlin}, pages = {1391 -- 1394}, 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{GeyerSchneehagenHeroldetal., author = {Geyer, Thomas and Schneehagen, Erik W. and Herold, Gert and Zhang, Tingyi and Moreau, Danielle J.}, title = {Reduction of rotor aerodynamic noise using porous blade tips}, series = {Fortschritte der Akustik - DAGA, 50. Jahrestagung f{\"u}r Akustik}, journal = {Fortschritte der Akustik - DAGA, 50. Jahrestagung f{\"u}r Akustik}, pages = {4}, abstract = {Motivated by promising results from experiments on the noise reduction performance of finite wall-mounted airfoils with a porous tip in an aeroacoustic wind tunnel, corresponding measurements were performed in a dedicated rotor test rig. This rig features a 3 kW direct-drive electric motor with three rotor blades of 1.1 m diameter. In the experiments, a variety of different tip modifications was tested regarding their noise reducing performance, including different porous materials that were manufactured using rapid prototyping. Acoustic measurements were performed at different rotationals speeds and blade angles using a ring-shaped microphone array consisting of 60 evenly spaced microphones. The rotational speed was measured using a laser sensor. Different beamforming algorithms were used in post-processing to help analyzing the data. The results show that porous tips can lead to a notable noise reduction at low frequencies, but a small penalty at medium and high frequencies which may be due to the surface roughness of the porous tips. This trend seems more severe for lower blade angles than for higher ones. These findings agree well with those obtained from the previous wind tunnel measurements.}, language = {en} }