Comparison of acoustic pulse propagation between scale-model measurements and three-dimensional simulation over real-life urban topography

ABSTRACT In Inter-Noise 2013, the authors presented a study comparing acoustic propagation measurements over a 1:100 scale model of a real-life urban topography and large-scale three-dimensional finite-difference timedomain simulations. The results were presented in octave-band sound pressure levels. As a sequel to the 2013 paper, this paper compares the results in time domain. The waveforms of acoustic pulse propagation are computed by inverse filtering the source responses of an electric spark generator of the measurements and a Gaussian pulse of the simulation. The results show excellent matches at line-of-sight and single diffraction receiver positions in overall waveform structure, especially in arrival times of the diffracted and reflected pulses. The arrival time matched even after 0.7 s of traveling time. However, major discrepancies are observed at a receiver position which is affected by a combination of double diffraction and multiple reflections and positions affected by deep triple diffractions. Furthermore, in such positions, the simulated waveforms are found to have more energy in higher frequency. The discrepancies are possibly attributed to the use of rigid surfaces in the simulation and the lack of air absorption correction in the measured data processing.