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2014
Conference Paper
Titel
Simulation of the 3D Sound Propagation and Radiation of a Railway Air Conditioning Unit based on Transfer Matrix Techniques
Alternative
Simulation der Schallabstrahlung eines Bahnklimagerätes mithilfe von Transfermatrix Methoden
Abstract
The air conditioning unit (AC unit) is one of the major sound sources for exterior and interior noise of a railway vehicle. The design of such devices is a compromise between main functions like efficiency, fluid mechanics, thermodynamics and acoustics. Especially the acoustical behavior of an air conditioning unit needs to be quantified in every state of the development process, starting in an early design phase. For this purpose preferably simple and fast calculation tools are needed, which can be easily built up and adapted in a short time. Within a research project at the Fraunhofer Institute for Machine Tools and Forming Technology IWU an acoustical calculation model, based on transfer matrices of the different components, has been created to give a sufficiently accurate description of the sound power radiated by an AC unit. In a first step, the sound power of important sources has been characterized by measurement data. Furthermore, the acoustical transfer behavior of ducts and additional components like condensers or evaporators has been individually investigated and implemented in the model using transfer elements. Finally, the sources and transfer components were combined to give a complete representation of the acoustical properties of the air conditioning unit, which can be used for parameter variation studies and noise reduction.
Author(s)