The simplification of computer simulated persons (CSPs) in CFD models of occupied indoor spaces

This study presented an iterative approach to simplify computer simulated persons (CSPs) based on the mesh decimating algorithm [1]. The approach could largely simplify 3D-scanned manikins while maintaining their key geometrical features. The level of simplification could be quantified through controlling the iteration number of simplification. CFD computations of human thermal plume in a quiescent room were performed using CSPs with different levels of simplification. The numerical results were compared against the experimental data available in the literature. The results demonstrated that within the scope of this study, the CSP simplification only affected the predicted airflow field in the thermally-affected regions where the normalized air velocity was larger than 0.5. The predictive error increased with the dimensionless simplification index (SI). When SI was less than 3.5 × 10−4, the error induced by CSP simplification could be safely ignored. Contaminant transport in a densely occupied airliner cabin section was also simulated using the simplified CSPs. The results revealed that although the CSP simplification only affected airflow field prediction of the thermal plume regions, it could enlarge the predictive error of contaminant transport in the whole computational domain. In addition, this study found that the CSPs yielded from the algorithm were more numerically stable in terms of CFD computations.