Thermal and radiative effects

In addition to the problems of thermal comfort and urban heat islands, thermal effects play an important role in the movement of air masses in the atmosphere and, consequently, in the dispersion of atmospheric pollutants. Therefore, a thermal module added to a radiative module related to sunshine has been developed and integrated to the AIR&D 3D model to address this issue as well as the urban heat island issue.

Our published research:

Effects of wind speed and atmospheric stability on the air pollution reduction rate induced by noise barriers

Influence of depressed road configuration on downwind pollutant concentrations: A CFD study under various thermal stability conditions

Pollen

Pollen is by definition an air pollutant, as it can affect human health and well-being. Because of the particular aspect of this type of particles, the model usually used by AIR&D is not sufficient. Therefore, a pollen dispersion module has been developed and integrated to the 3D model developed by AIR&D.

This module was used to model the transport of pollen from trees located on Place de la République in Strasbourg.

Canyon street effect

A canyon street is a street, usually narrow, with buildings on either side of it following each other over a large distance. Recirculation phenomena are observed in this type of street, leading to higher concentrations of air pollutants. The concentrations are more or less high depending on the characteristics of the street (height of the upstream and downstream buildings, width and length of the street).

Our published research:

CFD evaluation of mean pollutant concentration variations in step-down street canyons

Annual average values

The modelling results do not allow direct comparison with the regulatory values prescribed by the European Union, or the guide values given by the World Health Organization. Indeed, the calculation of annual average concentration values requires the consideration of a large set of parameters (wind speed, wind direction, emissions, etc.). To overcome this problem, an innovative methodology has been developed by AIR&D.

Our published research :

Methodologies to assess mean annual air pollution concentration combining numerical results and wind roses

Vegetation

Vegetation is an essential element in the context of urban planning. However, its mode of action on airflow and the dispersion of air pollutants is much more complex than that of buildings. Therefore, a vegetation module has been developed to take into account the effects of vegetation on airflow, the turbulence generated and the transport of air pollutants, and has been integrated into the AIR&D 3D model.Methodologies to assess mean annual air pollution concentration combining numerical results and wind roses