Traffic with Noise Modeling Consideration of Meteorological Effect

Under certain meteorological conditions, traffic noise which would usually propagate upwards is refracted back down, thus resulting in an increase in noise level at residential buildings. To take into account such meteorological effects, it is therefore necessary to model the atmospheric refraction. Algorithms for atmospheric refraction modeling, however, are missing in all commonly used traffic noise models, albeit some models consider atmospheric absorption related to weather effects. This paper presents a traffic noise model with consideration of atmospheric refraction effect. The new model combines the well established CRTN noise model with an empirical atmospheric refraction model to incorporate meteorological effects. Large eddy simulations are first performed in OpenFOAM to simulate the atmospheric flow in a typical urban setting. Grid refinement studies have been carried out, and a dynamic Lagrangian sub-grid model has been employed to ensure realistic wind and temperature fields are achieved. Time-averaged values of meteorological parameters including wind speed, wind shear, and lapse rate are obtained at the noise modeling observation points, and subsequently fed into the CRTN noise model combined with the atmospheric refraction model. The traffic noise level at residential buildings is computed by the in-house developed based on the combined model.