@inproceedings{GeyerSarradjRexetal., author = {Geyer, Thomas and Sarradj, Ennes and Rex, Christoph and Kießling, Sebastian and Neefe, Alexander}, title = {Messung der Schallcharakteristik einer Mikrogasturbine}, series = {Fortschritte der Akustik, DAGA 2015, N{\"u}rnberg, 41. Jahrestagung f{\"u}r Akustik, 16. - 19. M{\"a}rz 2015}, booktitle = {Fortschritte der Akustik, DAGA 2015, N{\"u}rnberg, 41. Jahrestagung f{\"u}r Akustik, 16. - 19. M{\"a}rz 2015}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, address = {Berlin}, isbn = {978-3-939296-08-9}, language = {de} } @misc{GeyerSarradjRexetal., author = {Geyer, Thomas and Sarradj, Ennes and Rex, Christoph and Kießling, Sebastian and Neefe, Alexander}, title = {Schallemission einer Mikrogasturbine}, series = {L{\"a}rmbek{\"a}mpfung}, journal = {L{\"a}rmbek{\"a}mpfung}, number = {6}, issn = {1436-4999}, pages = {268 -- 272}, language = {de} } @misc{GeyerSarradj, author = {Geyer, Thomas and Sarradj, Ennes}, title = {Circular Cylinders with Soft Porous Cover for Flow Noise Reduction}, series = {Experiments in Fluids}, volume = {57}, journal = {Experiments in Fluids}, number = {3}, issn = {0723-4864}, doi = {10.1007/s00348-016-2119-7}, pages = {30}, abstract = {The use of porous materials is one of several approaches to passively control or minimize the generation of flow noise. In order to investigate the possible reduction of noise from struts and other protruding parts (for example components of the landing gear or pantographs), acoustic measurements were taken in a small aeroacoustic wind tunnel on a set of circular cylinders with a soft porous cover. The aim of this study was to identify those materials that result in the best noise reduction, which refers to both tonal noise and broadband noise. The porous covers were characterized by their air flow resistivity, a parameter describing the permeability of an open-porous material. The results show that materials with low air flow resistivities lead to a noticeable flow noise reduction. Thereby, the main effect of the porous cylinder covers is that the spectral peak of the aeolian tone due to vortex shedding appears much narrower, but is not suppressed completely. Based on the measurement results, a basic model for the estimation of the total peak level of the aeolian tone was derived. In addition to the minimization of the vortex shedding noise, a reduction of broadband noise can be observed, especially at higher Reynolds numbers. The noise reduction increases with decreasing air flow resistivity of the porous covers, which means that materials that are highly permeable to air result in the best noise reduction.}, language = {en} } @misc{GeyerWasalaCateretal., author = {Geyer, Thomas and Wasala, Sahan and Cater, John and Norris, Stuart and Sarradj, Ennes}, title = {Experimental Investigation of Leading Edge Hook Structures for Wind Turbine Noise Reduction : AIAA paper 2016-2954}, series = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016, Vol. 5}, journal = {22nd AIAA/CEAS Aeroacoustics Conference 2016, Lyon, France, 30 May-1 June 2016, Vol. 5}, publisher = {Curran Associates}, address = {Red Hook, NY}, isbn = {978-1-5108-2672-4}, pages = {3853 -- 3865}, language = {en} } @misc{GeyerClausSarradjetal., author = {Geyer, Thomas and Claus, Vanessa and Sarradj, Ennes and Markus, Philipp}, title = {Silent Owl Flight: The Effect of the Leading Edge Comb on the Gliding Flight Noise : AIAA paper 2016-3017}, 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 = {4885 -- 4896}, language = {en} } @inproceedings{GeyerSarradjHobracht, author = {Geyer, Thomas and Sarradj, Ennes and Hobracht, Marcus}, title = {Noise generated by a leading edge in anisotropic turbulence}, series = {45th International Congress and Exposition on Noise Control Engineering (Internoise 2016), Hamburg, Germany, 21-24 August 2016, vol. 8}, booktitle = {45th International Congress and Exposition on Noise Control Engineering (Internoise 2016), Hamburg, Germany, 21-24 August 2016, vol. 8}, editor = {Kropp, Wolfgang and Estorff, Otto von and Schulte-Fortkamp, Brigitte}, publisher = {Curran Associates}, address = {Red Hook, NY}, isbn = {978-1-5108-2988-6}, pages = {6067 -- 6078}, language = {en} } @inproceedings{GeyerSarradj, author = {Geyer, Thomas and Sarradj, Ennes}, title = {Experimentelle Untersuchung der Minderung von Str{\"o}mungsschall durch por{\"o}se Zylinderummantelungen}, 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{KampsGeyerSarradjetal., author = {Kamps, Laura and Geyer, Thomas and Sarradj, Ennes and Br{\"u}cker, Christoph}, title = {Vortex shedding noise of a cylinder with hairy flaps}, series = {Journal of Sound and Vibration}, volume = {388}, journal = {Journal of Sound and Vibration}, issn = {0022-460X}, doi = {10.1016/j.jsv.2016.10.039}, pages = {69 -- 84}, language = {en} } @inproceedings{BrueckerKampsGeyeretal., author = {Br{\"u}cker, Christoph and Kamps, Laura and Geyer, Thomas and Sarradj, Ennes}, title = {Wake-Vortex Sound Attenuation using Attached Hairy Flaps}, 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 = {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} }