Former Academic Staff

Common measures in noise abatement strategies of traffic noise are noise barriers. These represent a reliable and well calculable Method. On the other hand due to the required height of conventional barriers they are quite expensive and also they hinder the view of the landscape. As railway noise radiation mainly originates from the rail-wheel contact zone the application of shrouds in combination with low barriers seems to be promising. Assuming a radiation of the rails only in the vicinity of the wheels shrouds can be limited to the bogies. To date investigations dealt mainly with the dimensions of shroud-barrier systems, whereas this work focuses on the attributes of the inner surfaces. In addition to absorbing surfaces especially acoustically soft surfaces of very low acoustic impedance are accounted for. The examination of the influence of the surface impedances begins at a simulation of two different geometries using a wave approach. The calculated surface-based insertion losses are verified through the implementation of the finite-element-method and through measurements on a shroud-barrier model. In a concluding chapter the feasibility and the estimated total insertion loss of optimised surface combinations are discussed.

Dissertation: http://opus.kobv.de/tuberlin/volltexte/2005/1022/

Supervisor : Möser, Michael; Prof. Dr.-Ing.