ZURUECK HOCH VOR INHALT SUCHEN

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Proposing Institution

Fachgebiet für Strömungsbeeinflussung und Aeroakustik, Fakultät Maschinenwesen, TU München
Project Manager

Prof. Dr.-Ing. Hans-Jakob Kaltenbach
Boltzmannstr. 15
85748 Garching
Abstract
Splitter attenuators are a common type of dissipative silencers that are installed in exhaust stacks of power plants in order to prevent the noise that is emitted from the gas turbine to radiate into the surroundings. The performance of such silencers is limited by the fact that the gas flow passing through the gaps between the silencer baffles at speeds up to 20 m/s is producing flow noise. The project deals with the numerical investigation of the sources of self-noise by using hybrid simulation approaches of computational aeroacoustics, including unsteady, three-dimensional flow simulation (Large Eddy Simulation) and Lighthills analogy for modeling acoustic sources. Three configurations will be studied: (i) for a single baffle in a free surrounding the influence of tapering the trailing edge on the sound radiation into the far-field is studied using compressible CFD results along a porous control surface as input for a Ffowcs-Williams Hawkings solver. (ii) Next, excitation of acoustic duct modes from flow along a single silencer baffle enclosed in a rectangular duct subject to turbulent flow is investigated. (iii) Finally, the noise associated with the grazing flow along the perforated metal surface enclosing the cushions of sound absorbing materials is studied for a small panel of the surface consisting of a pattern of shallow cavities.

Impressum, Conny Wendler