An efficient and reliable method to model edge diffraction is required in view of further developing the computer simulation of rooms. Despite the sophisticated numerical approaches already available a parallel experimental validation is needed in order to better understand the merits and efficacy of the edge diffraction modeling. In this work the Svensson-Andersson-Vanderkooy time domain modeling was tested by comparing with a set of experimental measurements taken in a 1:20 scale model of an ancient theatre. In fact the tiers of steps of an ancient theatre consisting of the cavea alone are an ideal benchmark to model edge diffraction. In this type of space the impulse response consists of two geometrical components (direct and floor reflection) and the tail is made up by diffracted sound only. In the work the 1:20 scale model of the Greek theatre in Syracuse was set up to meet these conditions. Although some geometrical limits of the numerical model in the version here employed, it was possible to correlate theoretical and experimental results under few conditions and for a number of seating positions. Within the above limits the edge diffraction modeling provided a reliable impulse response particularly in the lower part of the cavea.
Validation of a numerical code for edge diffraction by means of acoustical measurements on a scale model of an ancient theatre
FARNETANI, Andrea;PRODI, Nicola;FAUSTI, Patrizio
2011
Abstract
An efficient and reliable method to model edge diffraction is required in view of further developing the computer simulation of rooms. Despite the sophisticated numerical approaches already available a parallel experimental validation is needed in order to better understand the merits and efficacy of the edge diffraction modeling. In this work the Svensson-Andersson-Vanderkooy time domain modeling was tested by comparing with a set of experimental measurements taken in a 1:20 scale model of an ancient theatre. In fact the tiers of steps of an ancient theatre consisting of the cavea alone are an ideal benchmark to model edge diffraction. In this type of space the impulse response consists of two geometrical components (direct and floor reflection) and the tail is made up by diffracted sound only. In the work the 1:20 scale model of the Greek theatre in Syracuse was set up to meet these conditions. Although some geometrical limits of the numerical model in the version here employed, it was possible to correlate theoretical and experimental results under few conditions and for a number of seating positions. Within the above limits the edge diffraction modeling provided a reliable impulse response particularly in the lower part of the cavea.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
