Miniaturising a Wall Test Facility

Abstract

Many problems in building acoustics are expensive and time-consuming to study because of the construction costs. To avoid such costs, physical models can be used. In room acoustics, where mainly airborne sound fields are examined, this is a common method. Scaling down a building acoustics problem is, however, more complex because structure-borne sound and sound transmission to other elements or rooms must be taken into account. This paper deals with scaling down a building acoustics measurement object by reference to full scale performance. Basic scaling rules are derived and the scaling of the acoustics quantities is analysed. The requirements of measurement devices and methods are discussed. As an example, the design of a scaled version of a wall test facility is described. Construction details and measurements on model scale are presented. Validation with full scale test facilities confirms the results. It is shown that scale models are suitable for studying fundamental problems in building acoustics.