Efficiency of screen application in built-up area

摘要

In the paper, the procedure based on the simulation program is used to predict the screen efficiency in an urban system. The efficiency variation depending on a growing complexity of an applied source model and propagation space model is shown. A road as noise source is modelled by an appropriate set of point sources representing moving vehicles divided in classes depending on their noise emission. Thus, road lane structure, vehicle speeds and traffic composition are considered. A propagation space model, apart from a protected building, considers other present objects in road surroundings. The unique image method applied for propagation description is based on the sound pressure summation over wave paths to an observation point. The wave paths are represented by the ordered chains of multiple interactions. They include transmission, reflection and diffraction at obstacles' wedges which can appear at arbitrary place in the chains. The case studies are presented to highlight the significance of a source and its surroundings parameters appearing as a consequence of growing accuracy in the modelling, approaching the real urban system conditions.