@inproceedings{RetkaHawkingsMarburg, author = {Retka, Stefanie and Hawkings, Stuart C. and Marburg, Steffen}, title = {Acoustic Radiation Problem of a Recorder Fluid}, series = {Proceedings of the 9th International Conference on Theoretical and Computational Acoustics, Dresden}, booktitle = {Proceedings of the 9th International Conference on Theoretical and Computational Acoustics, Dresden}, editor = {Marburg, Steffen}, pages = {129 -- 134}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Modal Analysis of a Fluid inside and around a Recorder}, series = {Proceedings of NAG/DAGA 2009, International Conference on Acoustics, Rotterdam}, booktitle = {Proceedings of NAG/DAGA 2009, International Conference on Acoustics, Rotterdam}, editor = {Boone, M. M.}, pages = {228 -- 229}, language = {en} } @inproceedings{RetkaHervellaNietoMarburg, author = {Retka, Stefanie and Hervella-Nieto, Luis and Marburg, Steffen}, title = {Vergleich der akustischen Finite-Elemente-L{\"o}sungen zu Eigenwertproblem und Quellproblem mit Raviart-Thomas- sowie Lagrange-Elementen}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 34. Jahrestagung f{\"u}r Akustik, Dresden}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 34. Jahrestagung f{\"u}r Akustik, Dresden}, editor = {Jekosch, U. and Hoffmann, R.}, pages = {79 -- 80}, language = {de} } @article{RetkaHervellaNietoMarburg, author = {Retka, Stefanie and Hervella-Nieto, Luis and Marburg, Steffen}, title = {Comparison of pressure and displacement formulations for finite elements in linear time-harmonic acoustics}, series = {Computers and Structures}, journal = {Computers and Structures}, publisher = {151}, doi = {10.1016/j.compstruc.2015.01.009}, pages = {459 -- 57}, abstract = {In this article, we compare the finite element solution of the pressure and the displacement formulations for the acoustic problem in the frequency domain. The Helmholtz differential equation is solved for both, the spectral and the source problems, and each of these is formulated in terms of pressure and displacement. The pressure formulation allows to use standard Lagrangian elements whereas Raviart-Thomas elements are applied for the displacement formulation. Both formulations are tested in several examples. It is shown that Raviart-Thomas elements account for a reasonable alternative to Lagrangian elements in some cases.}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Open Bottles - Helmholtz resonator and quarter wave effect}, series = {AIA-DAGA - Proceedings of the International Conference on Acoustics, Meran}, booktitle = {AIA-DAGA - Proceedings of the International Conference on Acoustics, Meran}, editor = {Peretti, A. and Scheuren, J.}, pages = {1197 -- 1198}, language = {en} } @article{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {An infinite element for the solution of Galbrun equation}, series = {ZAMM - Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik}, volume = {93}, journal = {ZAMM - Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik}, number = {2-3}, pages = {154 -- 162}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Modal analysis of a fluid in an unbounded domain with finite and infinite elements}, series = {Proceedings of NOVEM 2012 - Noise and Vibration: Emerging Methods, Sorrento}, booktitle = {Proceedings of NOVEM 2012 - Noise and Vibration: Emerging Methods, Sorrento}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Modalanalyse eines str{\"o}menden Fluids mit finiten und infiniten Elementen}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 38. Jahrestagung f{\"u}r Akustik, Darmstadt}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 38. Jahrestagung f{\"u}r Akustik, Darmstadt}, editor = {Hanselka, H.}, pages = {557 -- 558}, language = {de} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Numerical computations of a fluid inside and around a recorder}, series = {Proceedings of Forum Acusticum 2011, Aalborg, D{\"a}nemark}, booktitle = {Proceedings of Forum Acusticum 2011, Aalborg, D{\"a}nemark}, pages = {145 -- 147}, abstract = {We present the sound propagation and sound radiation inside and around a three dimensional recorder model. The fluid inside and in the near field of the instrument is meshed by second order Lagrangian tetrahedra elements. To present the effects in the far field, infinite elements are added to the finite elements. As infinte elements we use complex conjugated Astley-Leis elements. The goal of our studies is the computation of the eigenmodes of all playable notes, as well as the determination of the radiation behaviour for different fingerings. In a first step, the results obtained by considering a static fluid are presented. When playing a recorder, the inserted air flow leads to an oscillation of the air column inside the instrument. The musician is able to influence the frequency of the note by varying the blowing pressure and therefore a fine-tuning of the sound can be achieved. In rotation afflicted flows, the sound propagation can be described by the Galbrun equation. In a first instance, we present the influence of the flow velocity on the eigenfrequencies for simple geometries. Those results are compared to the frequencies obtained with Helmholtz equation for static fluids.}, language = {en} } @inproceedings{MarburgRetkaMoebius, author = {Marburg, Steffen and Retka, Stefanie and M{\"o}bius, Franziska}, title = {Simulation and Experiment for Intonation of a Recorder}, series = {Analysis and description of music instruments using engineering methods, Halle}, booktitle = {Analysis and description of music instruments using engineering methods, Halle}, editor = {Birnbaum, C. and Ehricht, S. and Kaliske, M. and Saft, S.}, pages = {42 -- 49}, language = {en} } @article{RetkaHawkingsMarburg, author = {Retka, Stefanie and Hawkings, Stuart C. and Marburg, Steffen}, title = {An eigenvalue search algorithm for the modal analysis of a resonator in free space}, series = {Journal of Computational Acoustics}, volume = {19}, journal = {Journal of Computational Acoustics}, number = {1}, pages = {95 -- 109}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Numerische Berechnung eines Fluids innerhalb und um einer Blockfl{\"o}te}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 37. Jahrestagung f{\"u}r Akustik, D{\"u}sseldorf}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 37. Jahrestagung f{\"u}r Akustik, D{\"u}sseldorf}, editor = {Becker-Schweitzer, J. and Notbohm, G.}, pages = {819 -- 820}, language = {de} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Numerical Modal Analysis of a Recorder Fluid}, series = {Proceedings of 20th International Symposium on Music Acoustics (Associated Meeting of the International Congress on Acoustics), ISMA 2010, Sydney and Katoomba}, booktitle = {Proceedings of 20th International Symposium on Music Acoustics (Associated Meeting of the International Congress on Acoustics), ISMA 2010, Sydney and Katoomba}, editor = {Smith, J.}, pages = {3}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Numerical computations of a recorder fluid}, series = {Proceedings of 20th International Congress on Acoustics, ICA 2010}, booktitle = {Proceedings of 20th International Congress on Acoustics, ICA 2010}, editor = {Burgess, M. and Davey, J. and Don, C. and McMinn, T.}, pages = {3}, language = {en} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Simulation der Schallausbreitung am Beispiel einer Blockfl{\"o}te}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 36. Jahrestagung f{\"u}r Akustik, Berlin}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 36. Jahrestagung f{\"u}r Akustik, Berlin}, editor = {M{\"o}ser, M. and Schulte-Fortkamp, B. and Ochmann, M.}, pages = {453 -- 454}, language = {de} } @inproceedings{RetkaMarburg, author = {Retka, Stefanie and Marburg, Steffen}, title = {Numerische Modalanalyse einer Sopranblockfl{\"o}te}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 36. Jahrestagung f{\"u}r Akustik, Berlin}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 36. Jahrestagung f{\"u}r Akustik, Berlin}, editor = {M{\"o}ser, M. and Schulte-Fortkamp, B. and Ochmann, M.}, pages = {103 -- 104}, language = {de} } @inproceedings{MichaelisMarburgRetka, author = {Michaelis, Thomas and Marburg, Steffen and Retka, Stefanie}, title = {Application of the Transfer Path Analysis to Vehicle Doors}, series = {INTER-NOISE and NOISE-CON Congress and Conference Proceedings, Glasgow}, volume = {265}, booktitle = {INTER-NOISE and NOISE-CON Congress and Conference Proceedings, Glasgow}, number = {4}, publisher = {Institute of Noise Control Engineering}, doi = {10.3397/IN_2022_0551}, pages = {3878 -- 3885}, abstract = {Transfer path analysis (TPA) is a proven method for identifying critical structure-borne and airborne sound paths. The basic idea is to divide the overall system into an exciting active component (source) and a passive component, e.g. the mechanical structure to be investigated, with their respective measurement points. By separating them, two independent systems are created, whereby on one hand, the excitation behaviour can be characterised and on the other hand, the transmission behaviour can be assessed. Finally, both systems are validated by comparing them to each other and deciding whether changes to source or structure are required or not. The advantage is the simple description of the source as a black box without complex modelling. In this contribution, this systematic is applied to window regulator systems as they are found in vehicles. The focus is on a hybrid approach between experimental and numerical transfer path analysis. For this purpose, the basic workflow of suitable TPA methods is discussed. This includes the operational measurement of different exciting electric motors variants, the determination of the transfer functions of the structure, the calculation of the contact forces and the analysis of the individual transfer paths.}, language = {en} } @inproceedings{MichaelisMarburgRetka, author = {Michaelis, Thomas and Marburg, Steffen and Retka, Stefanie}, title = {D{\"a}mpfungsidentifikation von Leichtbaustrukturen}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 49. Jahrestagung f{\"u}r Akustik, Hamburg}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 49. Jahrestagung f{\"u}r Akustik, Hamburg}, pages = {1338 -- 1341}, language = {de} } @inproceedings{MichaelisMarburgRetka, author = {Michaelis, Thomas and Marburg, Steffen and Retka, Stefanie}, title = {Transferpfadanalyse von Fensterhebersystemen}, series = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 48. Jahrestagung f{\"u}r Akustik, Stuttgart}, booktitle = {Fortschritte in der Akustik - Plenarvortr{\"a}ge und Fachbeitr{\"a}ge der 48. Jahrestagung f{\"u}r Akustik, Stuttgart}, pages = {447 -- 450}, language = {de} } @inproceedings{MichaelisMarburgRetka, author = {Michaelis, Thomas and Marburg, Steffen and Retka, Stefanie}, title = {D{\"a}mpfungsidentifikation von Leichtbaustrukturen}, editor = {Deutsche Gesellschaft f{\"u}r Akustik e.V. (DEGA),}, publisher = {DAGA - 49. Jahrestagung f{\"u}r Akustik}, isbn = {978-3-939296-21-8}, pages = {1338-1341}, abstract = {Leichtbaustrukturen kommen in vielen Branchen und Bereichen zum Einsatz. Vor allem der Fahrzeugbau sowie die Luft- und Raumfahrt profitieren von dem geringen Materialeinsatz und der Einsparung in der Nutzungsphase. Neben den genannten Potenzialen bieten Leichtbaustrukturen die M{\"o}glichkeit, gezielt eine hohe D{\"a}mpfung von Vibrationen bei geringem Materialeinsatz zu kombinieren. In diesem Zusammenhang werden h{\"a}ufig sog. Sandwichstrukturen verwendet. Die Sandwichstrukturen bestehen in der Regel aus kraftaufnehmenden Deckschichten und weicheren Kernschichten aus einer Wabenstruktur oder Vollmaterial aus Kunststoffen. Letztere {\"u}bernehmen h{\"a}ufig die Aufgabe der D{\"a}mpfung. In diesem Beitrag wird die D{\"a}mpfung einer ebenen Sandwichstruktur bestehend aus einer metallischen Deckschicht und einer viskoelastischen Polymerschicht untersucht. Die Herausforderung liegt in der physikalischen Modellierung der Materiald{\"a}mpfung sowie der {\"U}bertragung der experimentell gewonnenen Daten in ein Finite-Elemente Simulationsmodell. Hierzu werden bestehende Methoden der D{\"a}mpfungsidentifikation evaluiert. Anschließend wird die Struktur mithilfe einer experimentellen Schwingungsanalyse unter vorgegebenen Randbedingungen analysiert. Aus den gewonnenen Messdaten werden Parameter ermittelt, um ein frequenzabh{\"a}ngiges Materialmodell zu generieren. Neben dem Vergleich der experimentellen und berechneten Ergebnisse liegt der Schwerpunkt dieses Beitrags auf der Betrachtung von Unsicherheiten w{\"a}hrend des Prozesses.}, language = {de} }