Convective transfer of a conditional admixture within urban geometry

Abstract

The paper studies the process of a heavy impurity propagation in urban geometry. As an object of research, a three-dimensional layout of a part of the city of Perm was used. It reproduces the height and location of buildings as well as terrain features on an area of about 5 km². The model was placed in a container with water; aqueous solutions of NaCl were used as an impurity. The experimental parameters were selected based on the approximation of turbulent characteristics and qualitatively describe the process of propagation of the carbon dioxide/air mixture. Experiments were performed for localized and extended impurity sources. It is shown that the terrain plays an essential role in the process of impurity propagation. The admixture tends to fill the lowest areas of the relief. The presence of buildings prevents the movement of impurities. In some cases, this can lead to the formation of stagnant zones with a high impurity content.