Abstract
Curtain walls present critical aspects related to noise insulation. Laboratory and field tests are traditionally the most used procedure to determine sound transmission loss. Even if they provide the best results, they are very expensive, time-consuming (at least two days) and the results are specific of the tested specimen and therefore they cannot be generalized. Conversely, traditional numerical used simulations are generally conducted through Statistical Energy Analysis (SEA) studies or analytical analysis. Both approaches do not offer reliable results as they need several laboratory tests and dedicated mathematical models.
Thus, the aim of this research is to compute the curtain wall sound insulation by means of a combined simulation approach, using TMM and 3D acoustic model. The calibration and validation of this procedure is discussed in comparison with laboratory tests. Poroelastic materials as well as rigid metal stud are carefully characterized and sound source and sound field within both measured and simulated environment are calibrated and validated. Measurements are then compared with simulated transmission loss and a parametric study for mullions structure and their components is reported.
Results clearly show how it is possible to completely simulate a laboratory test combining 3D simulation and Transfer Matrix Method results and how the influence of mullion components is of paramount importance for the final acoustical performances.