Envi-MET validation and sensitivity analysis using field measurements in a hot arid climate

Abstract

Envi-MET is a computational fluid dynamics (CFD) modelling software that analyses interactions between the microclimate and the built environment through simulation, predicting parameters such as wind speed, air temperature and thermal comfort indices. The large number of variables and calculations involved makes validating Envi-MET models difficult. This study focuses on the validation of Envi-MET through sensitivity and calibration testing. A site was chosen in a hot arid climate location. The testing involved measuring air temperature, relative humidity and wind speed at the site. For the sensitivity testing a hypothetical site was modelled with three scenarios for four variables (wind speed, relative humidity, albedo and grid size) set as low, base and high values. The monitoring study concluded that the accuracy of Envi-MET varied with the variable in question, showing a high correlation factor with wind speed and air temperature but a poor correlation with relative humidity, especially between 04:00 and 10:00. Envi-MET displayed different sensitivity levels, with a good response to variables change in wind speed and relative humidity, but little response to albedo changes.