Numerical coupling model to compute the microclimate parameters inside a street canyon: Part II: Experimental validation of air temperature and airflow

Abstract

Software and hardware systems have evolved rapidly in recent years. The numerical microclimate simulation is becoming an important tool for providing better information and analysis of thermal comfort, thermodynamic behaviors and energy consumption for a large range of urban configurations. This research is conducted over two parts. In the first part (Athamena et al., 2018), we have presented the development of a new numerical model based on full dynamic coupling process between the thermo-radiative software “Solene” and the CFD model “Code_Saturne”. The surface temperatures’ output results of coupled simulations were compared with the measurements data obtained during the EM2PAU1Etude Micro-Météorologique sur la Propagation Acoustique en milieu Urbain.1 experimental campaign. The comparisons showed that the coupling model reproduced the wall and ground surface temperatures quite well. This second part discusses the experimental validation concerning the air temperature and airflow results. Foremost, the measurement devices used during the EM2PAU experiment to measure air temperatures and average wind velocities inside the street canyon are detailed. Next, we present the inlet boundary conditions for the thermodynamic model. Following the same method used for surface temperatures, we have submitted the numerical results of air temperature, wind velocity and turbulent kinetic energy to an assessment with the statistical parameters and experimental data. The results indicate that the coupling model simulates the air temperatures and mean wind velocities at local scale adequately. On the others hand, the comparisons for turbulent kinetic energy highlight unsatisfactory results which are probably due to an erroneous representation of the inlet profiles of k and ɛ based on the theoretical formulations.