@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{SchulzGeyerThuermeretal., author = {Schulz, Adrian and Geyer, Thomas and Th{\"u}rmer, Konrad and Sarradj, Ennes and Stapel, Jennifer}, title = {Beachtung der Schallemission wasserwirtschaftlicher Anlagen im urbanen Raum}, series = {Bemessung im Wasserbau, Klimaanpassung, Unersuchungen, Regeln, Planung, Ausf{\"u}hrung, 40. Dresdner Wasserbaukolloquium 2017, 09.-10. M{\"a}rz 2017}, booktitle = {Bemessung im Wasserbau, Klimaanpassung, Unersuchungen, Regeln, Planung, Ausf{\"u}hrung, 40. Dresdner Wasserbaukolloquium 2017, 09.-10. M{\"a}rz 2017}, publisher = {Selbstverlag der Technischen Universit{\"a}t Dresden}, address = {Dresden}, isbn = {978-3-86780-509-4}, pages = {201 -- 210}, language = {de} } @inproceedings{Geyer, author = {Geyer, Thomas}, title = {Vom Eulenfl{\"u}gel zum leisen Tragfl{\"u}gel}, series = {Fortschritte der Akustik, 43. Deutsche Jahrestagung f{\"u}r Akustik, 6.-9. M{\"a}rz 2017 in Kiel}, booktitle = {Fortschritte der Akustik, 43. Deutsche Jahrestagung f{\"u}r Akustik, 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}, language = {de} } @inproceedings{GeyerSarradjWinkler, author = {Geyer, Thomas and Sarradj, Ennes and Winkler, Peggy}, title = {Messungen an einem Modell-Propellerpr{\"u}fstand}, 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 = {983 -- 986}, language = {de} } @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{GeyerKampsSarradjetal., author = {Geyer, Thomas and Kamps, Laura and Sarradj, Ennes and Br{\"u}cker, Christoph}, title = {Passive Control of the Vortex Shedding Noise of a Cylinder at Low Reynolds Numbers Using Flexible Flaps}, series = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3015)}, journal = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3015)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-504-3}, language = {en} } @misc{MoreauGeyerDoolanetal., author = {Moreau, Danielle J. and Geyer, Thomas and Doolan, Con and Sarradj, Ennes}, title = {Camber Effects on the Tonal Noise and Flow Characteristics of a Wall-mounted Finite Airfoil}, series = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3172)}, journal = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3172)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-504-3}, language = {en} } @misc{KampsBrueckerGeyeretal., author = {Kamps, Laura and Br{\"u}cker, Christoph and Geyer, Thomas and Sarradj, Ennes}, title = {Airfoil Self Noise Reduction at Low Reynolds Numbers Using a Passive Flexible Trailing Edge}, series = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3496)}, journal = {23rd AIAA/CEAS Aeroacoustics Conference 2017, Denver, USA, 5 June - 9 June 2017, (AIAA 2017-3496)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-504-3}, language = {en} } @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{GeyerClausHalletal., author = {Geyer, Thomas and Claus, Vanessa and Hall, Philipp and Sarradj, Ennes}, title = {Silent Owl Flight: The Effect of the Leading Edge Comb}, series = {International Journal of Aeroacoustics}, volume = {16}, journal = {International Journal of Aeroacoustics}, number = {3}, issn = {2048-4003}, pages = {115 -- 134}, language = {en} } @misc{GeyerSchulzThuermeretal., author = {Geyer, Thomas and Schulz, Adrian and Th{\"u}rmer, Konrad and Sarradj, Ennes and Stapel, Jennifer}, title = {Schallemission wasserwirtschaftlicher Anlagen}, series = {L{\"a}rmbek{\"a}mpfung}, journal = {L{\"a}rmbek{\"a}mpfung}, number = {3}, issn = {1436-4999}, pages = {99 -- 103}, language = {de} } @misc{PorteousGeyerMoreauetal., author = {Porteous, Ric and Geyer, Thomas and Moreau, Danielle J. and Doolan, Con}, title = {A correction method for acoustic source localisation in convex shear layer geometries}, series = {Applied Acoustics}, volume = {130}, journal = {Applied Acoustics}, issn = {0003-682X}, doi = {10.1016/j.apacoust.2017.09.020}, pages = {128 -- 132}, language = {en} } @inproceedings{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 = {4th Symposium on Fluid-Structure-Sound Interactions and Control, Tokio, 2017}, booktitle = {4th Symposium on Fluid-Structure-Sound Interactions and Control, Tokio, 2017}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7542-1}, pages = {337 -- 342}, language = {en} } @misc{GeyerPoppeSarradj, author = {Geyer, Thomas and Poppe, Willi and Sarradj, Ennes}, title = {Measurement of flow noise generation and pressure loss of nets and screens}, series = {Applied Acoustics}, volume = {134}, journal = {Applied Acoustics}, issn = {0003-682X}, doi = {10.1016/j.apacoust.2018.01.008}, pages = {69 -- 74}, 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{LuciusHuetterDietrichetal., author = {Lucius, Andreas and H{\"u}tter, Simon and Dietrich, Philipp and Schneider, Marc and Lehmann, Marius and Geyer, Thomas}, title = {Experimental and Numerical Investigation of Axial Fan Aeroacoustics at Disturbed Inflow Conditions}, series = {Fan 2018, International Conference on Fan Noise, Aerodynamics, Applications and Systems, Darmstadt 2018}, booktitle = {Fan 2018, International Conference on Fan Noise, Aerodynamics, Applications and Systems, Darmstadt 2018}, publisher = {CETIAT}, address = {Villeurbanne, France}, language = {en} } @inproceedings{KislerMaterneGeyeretal., author = {Kisler, Roman and Materne, Daniel and Geyer, Thomas and Sarradj, Ennes}, title = {Modularer Versuchsstand zur Charakterisierung von Plattenschalld{\"a}mpfern}, 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 = {441 -- 444}, language = {de} } @inproceedings{SchneehagenSarradjGeyer, author = {Schneehagen, Erik W. and Sarradj, Ennes and Geyer, Thomas}, title = {Numerische Simulation des Str{\"o}mungsger{\"a}usches eines wandb{\"u}ndigen Zylinders}, 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 = {1001 -- 1004}, language = {de} } @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} } @inproceedings{GeyerMoreauSarradjetal., author = {Geyer, Thomas and Moreau, Danielle J. and Sarradj, Ennes and Doolan, Con}, title = {Zur Schallentstehung an dreidimensionalen wandgebundenen Tragfl{\"u}gelprofilen}, 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 = {1587 -- 1590}, language = {de} } @inproceedings{Geyer, author = {Geyer, Thomas}, title = {Aeroakustische Schallquellen an Motoren und Aggregaten - Grundlagen und M{\"o}glichkeiten zur Minderung}, series = {Motor- und Aggregate-Akustik, 10. Magdeburger Symposium}, booktitle = {Motor- und Aggregate-Akustik, 10. Magdeburger Symposium}, editor = {Rottengruber, Hermann and Henze, Wilfried and Luft, Tommy}, address = {Magdeburg}, isbn = {978-3-944722-72-6}, doi = {10.25673/13410}, pages = {185 -- 206}, abstract = {Neben mechanischen und thermodynamischen Schallquellen kann es in Motoren und Aggregaten auch zu einer Entstehung von L{\"a}rm durch Str{\"o}mungen kommen. Ein wichtiges Beispiel daf{\"u}r ist die aerodynamische Schallentstehung an umstr{\"o}mten Festk{\"o}rpern, wie sie an zur K{\"u}hlung ben{\"o}tigten L{\"u}ftern auftreten kann. Im vorliegenden Beitrag sollen zuerst grundlegende Mechanismen der Schallentstehung an umstr{\"o}mten Tragfl{\"u}geln erl{\"a}utert und die maßgeblichen Einflussparameter spezifiziert werden. Das geschieht mit Hilfe einfacher Schallvorhersagemodelle und umfasst sowohl die Schallentstehung in einer turbulenten Str{\"o}mung sowie die Schallentstehung in einer quasi laminaren Str{\"o}mung durch die profileigene Grenzschicht. F{\"u}r beide F{\"a}lle lassen sich aus den Berechnungen bereits erste konstruktive Empfehlungen f{\"u}r eine m{\"o}glichst effektive L{\"a}rmminderung ableiten. In einem zweiten Schritt werden zus{\"a}tzlich Beispiele zur Minderung des str{\"o}mungsmechanisch erzeugten Schalls durch eine Modifikation der Tragfl{\"u}gel aufgef{\"u}hrt, die auf systematische Untersuchungen in einem aeroakustischen Windkanal zur{\"u}ckgehen. Das beinhaltet so wohl den Einsatz einer sinusf{\"o}rmigen Z{\"a}hnelung sowie eine Modifikation des Tragfl{\"u}gels mit por{\"o}sen Materialien.}, language = {de} } @misc{MoreauGeyerDoolanetal., author = {Moreau, Danielle J. and Geyer, Thomas and Doolan, Con and Sarradj, Ennes}, title = {Surface curvature effects on the tonal noise of a wall-mounted finite airfoil}, series = {The Journal of the Acoustical Society of America}, volume = {143}, journal = {The Journal of the Acoustical Society of America}, number = {6}, issn = {1520-8524}, doi = {10.1121/1.5040981}, pages = {3460 -- 3473}, abstract = {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.}, language = {en} } @misc{GeyerMoreauGiesleretal., author = {Geyer, Thomas and Moreau, Danielle J. and Giesler, Jens and Hall, Philipp and Sarradj, Ennes and Doolan, Con}, title = {Measurement of the noise generated by wall-mounted airfoils of different thickness}, series = {24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3796)}, journal = {24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3796)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-560-9}, language = {en} } @misc{GeyerSharmaSarradj, author = {Geyer, Thomas and Sharma, Sparsh and Sarradj, Ennes}, title = {Detached Eddy Simulation of the Flow Noise Generation of Cylinders with Porous Cover}, series = {24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3472)}, journal = {24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3472)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-560-9}, language = {en} } @misc{BiedermannCzeckayGeyeretal., author = {Biedermann, Till and Czeckay, Pasquale and Geyer, Thomas and Kameier, Frank and Paschereit, Christian Oliver}, title = {Noise Source Identification of Aerofoils Subjected to Leading Edge Serrations using Phased Array Beamforming}, series = {24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3794)}, journal = {24th AIAA/CEAS Aeroacoustics Conference 2018, Atlanta, USA, 25 June - 29 June 2018, (AIAA 2018-3794)}, publisher = {AIAA}, address = {Reston, Va}, isbn = {978-1-62410-560-9}, language = {en} } @inproceedings{TalboysGeyerBruecker, author = {Talboys, Edward and Geyer, Thomas and Br{\"u}cker, Christoph}, title = {The Aerodynamic And Aeroacoustic Effect Of Passive High Frequency Oscillating Trailing Edge Flaplets}, series = {IUTAM Symposium on Critical flow dynamics involving moving/deformable structures with design applications, Santorini, Greece, 2018}, booktitle = {IUTAM Symposium on Critical flow dynamics involving moving/deformable structures with design applications, Santorini, Greece, 2018}, pages = {12}, language = {en} } @misc{CaldichourySouliSarradjetal., author = {{\c{C}}aldichoury, I{\~n}aki and Souli, Mhamed and Sarradj, Ennes and Geyer, Thomas and Del Pin, Facundo}, title = {Numerical investigation of flow around hairy flaps cylinder using FSI Capabilities}, series = {The International journal of multiphysics}, volume = {12}, journal = {The International journal of multiphysics}, number = {2}, issn = {2048-3961}, pages = {189 -- 208}, language = {en} } @inproceedings{GeyerSarradj, author = {Geyer, Thomas and Sarradj, Ennes}, title = {Noise reduction and aerodynamics of airfoils with porous trailing edges}, series = {INTER-NOISE 2018, the 47th International Congress and Exposition on Noise Control Engineering, Chicago, Illinois, USA}, booktitle = {INTER-NOISE 2018, the 47th International Congress and Exposition on Noise Control Engineering, Chicago, Illinois, USA}, pages = {10}, language = {en} } @inproceedings{SharmaGeyerSarradj, author = {Sharma, Sparsh and Geyer, Thomas and Sarradj, Ennes}, title = {Time Domain Boundary Element Method for the Leading-Edge Noise subjected to Linear Vorticity}, series = {INTER-NOISE 2018, the 47th International Congress and Exposition on Noise Control Engineering, Chicago, Illinois, USA}, booktitle = {INTER-NOISE 2018, the 47th International Congress and Exposition on Noise Control Engineering, Chicago, Illinois, USA}, pages = {10}, language = {en} } @misc{GeyerLuciusSchroedteretal., author = {Geyer, Thomas and Lucius, Andreas and Schr{\"o}dter, Marcus and Schneider, Marc and Sarradj, Ennes}, title = {Reduction of Turbulence Interaction Noise Through Airfoils With Perforated Leading Edges}, series = {Acta Acustica united with Acustica}, volume = {105}, journal = {Acta Acustica united with Acustica}, number = {1}, issn = {1610-1928}, doi = {10.3813/AAA.919292}, pages = {109 -- 122}, language = {en} } @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{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{LuciusDietrichLehmannetal., author = {Lucius, Andreas and Dietrich, Philipp and Lehmann, Marius and Schneider, Marc and Geyer, Thomas}, title = {Schallquellenlokalisation aus CAA Simulationen von Ventilatorfl{\"u}geln mit Hilfe von Mikrofon-Array Techniken}, 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 = {Die CAA Simulation stellt ein wertvolles Hilfsmittel zum Verst{\"a}ndnis aeroakustischer Ph{\"a}nomene in Ventilatoren dar. Im Rahmen der Simulation werden große Mengen transienter Daten erzeugt, die ausgewertet werden m{\"u}ssen. Neben den Akustikergebnissen an geeigneten Mikrofonpositionen sind die transienten Daten aller Str{\"o}mungsgr{\"o}ßen im Nahfeld verf{\"u}gbar. Frequenzgefilterte Visualisierungen sowohl der Druckfluktuationen auf der Oberfl{\"a}che des Fl{\"u}gels als auch der akustischen Quellterme haben in den untersuchten F{\"a}llen nicht verl{\"a}sslich die relevanten Orte der Schallentstehung gezeigt. Bedingt durch Interferenzen im Nahfeld werden nicht alle Fluktuationen auf der Oberfl{\"a}che als Schall abgestrahlt. Der Einsatz von Mikrofon-Array Techniken zur Schallquellenlokalisation hat sich dagegen als eine sehr gut geeignete Methode herausgestellt. F{\"u}r einen stehenden und einen rotierenden Fl{\"u}gel wurden experimentell vorhandene Arrays in Simulationsmodellen nachgebaut. Die Akustik im Fernfeld wurde {\"u}ber die FW-H Gleichung bestimmt. Es zeigen sich in beiden F{\"a}llen {\"a}hnliche Quellverteilung und Quellst{\"a}rke in Experiment und Simulation. Zus{\"a}tzlich bietet die Simulation den Vorteil, ohne wesentlichen Mehraufwand beliebig viele frei positionierbare Mikrofone nutzen zu k{\"o}nnen. Die Ergebnisse zeigen, dass sich der Nachteil der sehr kurzen physikalischen Zeit einer Simulation durch diesen Freiheitsgrad ausgleichen l{\"a}sst. Die Analyse ist nicht nur im Hinblick auf physikalische Schallquellen hilfreich, sondern kann auch zur Lokalisierung von numerischem St{\"o}rschall genutzt werden.}, language = {de} } @misc{GeyerKarijasevic, author = {Geyer, Thomas and Karijasevic, Benjamin}, title = {Untersuchung der tonalen Schallentstehung umstr{\"o}mter Tragfl{\"u}gelprofile}, 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 = {Bildet sich bei der Umstr{\"o}mung eines Tragfl{\"u}gel- oder Schaufelprofils auf dessen Oberfl{\"a}che eine laminare Grenzschicht aus, so kommt es zu einer stark tonalen Schallentstehung. Diese {\"a}ußert sich durch eine sehr charakteristische spektrale Struktur, die sich aus deutlichen Hauptt{\"o}nen und weiteren kleineren Nebenmaxima zusammensetzt. Dieser Schallentstehungsmechanismus tritt meist bei niedrigen Str{\"o}mungsgeschwindigkeiten und Tragfl{\"u}gelnmit vergleichsweise geringer Sehnenl{\"a}nge auf, was in der Praxis vor allem bei Kompressoren, kleinen L{\"u}ftern, Mikrowindanlagen, U-Booten und kleinen unbemannten Luftfahrzeugen vorkommt. Im Beitrag werden die Ergebnisse einer Untersuchung an drei NACA0012-Tragfl{\"u}gelmodellenmit unterschiedlicher Sehnenl{\"a}nge (100 mm, 150 mm und 200 mm) vorgestellt, die im aeroakustischen Windkanal der Brandenburgischen Technischen Universit{\"a}t durchgef{\"u}hrtwurde. Dabei soll vor allem der Einfluss der Str{\"o}mungsgeschwindigkeit und der Sehnenl{\"a}nge, aber auch der des Anstellwinkels, auf die tonalen Charakteristiken dargestellt werden.}, language = {de} } @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} } @misc{GeyerAlShuga, author = {Geyer, Thomas and Al-Shuga, Nazar}, title = {Reduction of vortex shedding noise from finite, wall-mounted, circular cylinders using porous material}, 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 = {10.2514/6.2019-2695}, pages = {12}, language = {en} } @misc{BiedermannCzeckayGeyeretal., author = {Biedermann, Till and Czeckay, Pasquale and Geyer, Thomas and Kameier, Frank and Paschereit, Christian Oliver}, title = {Effect of Inflow Conditions on the Noise Reduction Through Leading Edge Serrations}, series = {AIAA Journal}, volume = {57}, journal = {AIAA Journal}, number = {9}, issn = {1533-385X}, doi = {10.2514/1.J057831}, language = {en} } @misc{TalboysGeyerPrueferetal., author = {Talboys, Edward and Geyer, Thomas and Pr{\"u}fer, Florian and Br{\"u}cker, Christoph}, title = {The aeroacoustic effect of different inter-spaced self-oscillating passive trailing edge flaplets}, series = {5th Symposium on Fluid-Structure-Sound Interactions and Control}, journal = {5th Symposium on Fluid-Structure-Sound Interactions and Control}, abstract = {An aeroacoustic investigating looking into the effect of changing theinter-spacing of passive self-oscillating trailing edge flaplets has been carried outusing a NACA0012 aerofoil. Clear differences can be observed between each ofthe inter-spacing cases. Where a reduction in low frequency noise, an increase inhigh frequency noise and a reduction in turbulence intensity in the wake can beseen for each case. As the inter-spacing is reduced, the differences become moreprominent when compared to the reference aerofoil.}, language = {en} } @misc{GeyerPeschel, author = {Geyer, Thomas and Peschel, Richard}, title = {The effect of flow-permeable material on the flow field and the aerodynamic noise of cylinders}, series = {23rd International Congress on Acoustics, Aachen, Germany}, journal = {23rd International Congress on Acoustics, Aachen, Germany}, pages = {5365 -- 5372}, language = {en} } @misc{LuciusSchneiderSchweitzerDeBortolietal., author = {Lucius, Andreas and Schneider, Marc and Schweitzer-De Bortoli, Stefan and Gerhard, Tom and Geyer, Thomas}, title = {Aeroacoustic simulation and experimental validation of sound emission of an axial fan applied in a heat pump}, series = {23rd International Congress on Acoustics, Aachen, Germany}, journal = {23rd International Congress on Acoustics, Aachen, Germany}, pages = {1851 -- 1858}, language = {en} } @misc{TalboysGeyerBruecker, author = {Talboys, Edward and Geyer, Thomas and Br{\"u}cker, Christoph}, title = {Influence of self-oscillating trailing edge flaplets on turbulent boundary layer - trailing edge noise}, series = {23rd International Congress on Acoustics, Aachen, Germany}, journal = {23rd International Congress on Acoustics, Aachen, Germany}, pages = {588 -- 595}, language = {en} } @misc{TalboysGeyerBruecker, author = {Talboys, Edward and Geyer, Thomas and Br{\"u}cker, Christoph}, title = {An aeroacoustic investigation into the effect of self-oscillating trailing edge flaplets}, series = {Journal of Fluids and Structures}, volume = {91}, journal = {Journal of Fluids and Structures}, issn = {1095-8622}, doi = {10.1016/j.jfluidstructs.2019.02.014}, pages = {13}, 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{ZhangMoreauGeyeretal., author = {Zhang, Tingyi and Moreau, Danielle J. and Geyer, Thomas and Fischer, Jeoffrey and Doolan, Con}, title = {Dataset on tip vortex formation noise produced by wall-mounted finite airfoils with flat and rounded tip geometries}, series = {Data in Brief}, volume = {28}, journal = {Data in Brief}, issn = {2352-3409}, doi = {10.1016/j.dib.2019.105058}, pages = {8}, language = {en} } @misc{ZhangMoreauGeyeretal., author = {Zhang, Tingyi and Moreau, Danielle J. and Geyer, Thomas and Fischer, Jeoffrey and Doolan, Con}, title = {Dataset on tip vortex formation noise produced by wall-mounted finite airfoils with sinusoidal and porous tip geometries}, series = {Data in Brief}, volume = {30}, journal = {Data in Brief}, issn = {2352-3409}, doi = {10.1016/j.dib.2020.105471}, pages = {10}, 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{Geyer, author = {Geyer, Thomas}, title = {Vortex Shedding Noise from Finite, Wall-Mounted, Circular Cylinders Modified with Porous Material}, series = {AIAA Journal}, volume = {58}, journal = {AIAA Journal}, number = {5}, issn = {1533-385X}, doi = {10.2514/1.J058877}, pages = {2014 -- 2028}, language = {en} } @misc{Geyer, author = {Geyer, Thomas}, title = {Measurement of the Turbulence Interaction Noise Generated by Flat Plates with Perforated Leading Edges}, series = {26th AIAA/CEAS Aeroacoustics Conference 2020, Virtual Event, 14 - 19 June 2020, virtual event}, journal = {26th AIAA/CEAS Aeroacoustics Conference 2020, Virtual Event, 14 - 19 June 2020, virtual event}, doi = {10.2514/6.2020-2576}, language = {en} } @misc{ArcondoulisLiuGeyeretal., author = {Arcondoulis, Elias and Liu, Yu and Geyer, Thomas and Sedaghatizadeh, Nima and Arjomandi, Maziar}, title = {Aeroacoustic performance of cylinders with a circumferential varying porous coating}, series = {26th AIAA/CEAS Aeroacoustics Conference 2020, Virtual Event, 14 - 19 June 2020, virtual event}, journal = {26th AIAA/CEAS Aeroacoustics Conference 2020, Virtual Event, 14 - 19 June 2020, virtual event}, doi = {10.2514/6.2020-2527}, language = {en} } @misc{OckerGeyerCzwielongetal., author = {Ocker, Christof and Geyer, Thomas and Czwielong, Felix and Kr{\"o}mer, Florian and Becker, Stefan and Merkel, Markus and Pannert, Wolfram}, title = {Experimental Investigation of the Impact of 3D-Metal-Printed Perforated Leading Edges on Airfoil and Axial Fan Noise}, series = {26th AIAA/CEAS Aeroacoustics Conference, Virtual Event, 14 - 19 June 2020, virtual event}, journal = {26th AIAA/CEAS Aeroacoustics Conference, Virtual Event, 14 - 19 June 2020, virtual event}, doi = {10.2514/6.2020-2529}, language = {en} } @misc{Geyer, author = {Geyer, Thomas}, title = {Experimental evaluation of cylinder vortex shedding noise reduction using porous material}, series = {Experiments in Fluids}, volume = {61}, journal = {Experiments in Fluids}, number = {7}, issn = {0723-4864}, doi = {10.1007/s00348-020-02972-0}, abstract = {The tonal noise generation of a circular cylinder in a uniform flow is an important source of aerodynamic noise. It can be found at parts of the landing gear of airplanes, at pantographs of trains, at antennas and basically all other protruding parts of vehicles. This noise is due to the periodic shedding of vortices along the cylinder span. One method to reduce this noise is the use of flow permeable covers around the cylinders. In the present study, measurements were performed in an aeroacoustic wind tunnel on a large set of porous covered cylinders. In addition to varying the porous material, which is characterized by its air flow resistivity and its porosity, the thickness of the porous layer was varied as well. The measurements were performed at Reynolds numbers between 14,000 and 103,000 using microphones located in the acoustic far field. It was found that the porous covers lead to a notable narrowing of the vortex shedding tonal peak in the sound pressure level spectra, an effect that increases with increasing porosity and thickness and decreasing air flow resistivity of the porous layer. Based on the large set of experimental data, basic trends were derived for the estimation of the vortex shedding Strouhal number and the reduction in the energy in the vortex shedding peak using the method of linear regression. Constant temperature anemometry measurements in the wake of selected cylinders basically showed a similar narrowing of the vortex shedding peak in the spectra of the turbulent velocity fluctuations. In addition, the measurement of wake profiles showed a reduction in the mean velocity and the turbulence in the wake as well as a widening of the wake region, while an analysis of the spanwise coherence revealed that the cause of the overall noise reduction is not a breakup of spanwise turbulent structures. Rather, the results imply that viscous damping of turbulent flow pressure amplitudes by the porous material strongly contributes to the noise reduction.}, language = {en} }