Sound levels forecasting for city-centers Part III: a road lane structure influence on sound level within urban canyon

Abstract

The computer simulation program PROP5 for prediction of the time-average sound level within an urban system has been exploited to analyze the sound level distribution in an urban canyon. The results obtained are presented in the series of papers (Walerian E, Janczur R. Sound levels forecasting for city-centers. Part I: Sound level due to a road within urban canyon. Applied Accoustics 62(4):359–80; Walerian E, Janczur R. Sound levels forecasting for city-centers. Part II: Effect of source model parameters on sound level in built-up area. Applied Acoustics 62(5):461–92; Janczur R, Walerian E, Czechowicz M. Sound levels forecasting for city-centers. Part IV: Vehicles stream parameters influence on a sound level distribution within canyon street. Applied Acoustics, in press) and the current paper is one of them. A roadway in the PROP5 program is modeled as a sum of individual vehicle drives-by. The multi-lanes roadway and different representations of sources for various classes of vehicles are allowed. During propagation, a wave interacting with obstacles undergoes multi-reflections from their walls and single and double diffraction at their wedges. In the paper, the same equivalent point source is used to represent all the vehicles and the same vehicle stream at each lane resulting in the equal vehicles' spacing is assumed. The PROP5 program is used to present the sound level distribution along building facades creating a canyon street and the sound level value at the ground floor as a function of a canyon width, road lane number, and the outer lane distance to a building facade.