Validation, verification, and quality control of computational fluid dynamics analysis for indoor environments using a computer-simulated person with respiratory tract

Computer-simulated persons (CSPs) with respiratory systems have been developed for microclimate analysis around the human body and inhalation exposure analysis, for detailed assessment of comfort and health risks in indoor spaces. This study examined and validated the prediction accuracy of a CSP, for precise estimation of indoor environmental quality (IEQ). The flow-field prediction accuracy was thoroughly examined in a grid analysis using the CSP and a thermal manikin for benchmarking. The model incorporated unsteady breathing and human postural sway, and assessed their impact on the microclimate around the human body. The numerically estimated flow field was validated using experimental particle image velocimetry (PIV) data, with a detailed grid independence test. Considering the practical use of the respiratory tract model for the inhalation exposure risk assessment, the prediction accuracy of particle transport and deposition analysis was examined using previously published in vivo experimental results. This analysis revealed that the impact of transient breathing and body vibrations on the reproduction of the thermal plume around the human body is quite weak; consequently, these conditions can be ignored from the macroscopic perspective of indoor airflow analysis.