Outdoor thermal comfort in urban neighbourhoods by coupling of building energy simulation and computational fluid dynamics

When evaluating the outdoor environment, it is essential to improve the accuracy of outdoor thermal comfort (OTC) modelling by investigating the simultaneous interactions of both convective and radiative fluxes. The majority of the existing models, however, employed to evaluate thermal comfort, do not consider these co-effects. This study aims to develop a novel and comprehensive framework for OTC modelling while using non-isothermal airflow and surface temperatures within street canyons. For this purpose, a dynamically coupled building energy simulation (BES) and computational fluid dynamics (CFD) model, previously developed by authors, is used to provide detailed analysis of convective fluxes. These values in addition to the simulated radiative heat fluxes are then utilized to calculate the OTC at a neighbourhood case study during a typical hot day. The results show substantial changes (6.5% higher) in the OTC results using the newly developed coupled model in comparison to traditional (standalone) approaches. For example, in the coupled approach, the OTC values experience a wider range which peaks to at noon . Moreover, physiological equivalent temperature (PET) values are higher which shows higher level of discomfort and heat stress range compared to the standalone models.