Development of reduced order flow responsive models of convective heat transfer for human body segments

With the increasing detail of thermal comfort studies, models need to represent the effects of spatial and temporal changes in conditions around the human body. Convection heat transfer varies significantly on the human body due to local airflow patterns. In many non-uniform flow scenarios different modes of convection show up depending on the airflow conditions. For example, flows through displacement ventilation or by mixing ventilation are commonly encountered in buildings and all result in substantially different convection regimes. Furthermore, the models are relevant for a number of areas such as automotive, aircraft and railway industries where local and dynamic effects under non-uniform conditions become significant. Therefore, there is a need to develop reduced order models that predict the convective heat transfer coefficients locally in non-uniform indoor flow conditions. The main aim of this research is to develop a reduced order model database that approximates the convective heat transfer coefficients (hc) of different body segments for typical indoor flow responses in multiple applications. Each application constitutes a definite structure in the database. This paper presents a first prototype of the developed reduced order database model where displacement ventilation flow regimes in rooms are detailed. The computational fluid dynamics (CFD) methodology is used to model airflow and heat transfer and also further to computationally evaluate the convective heat transfer coefficients for different body segments by temperature gradient analysis. In order to obtain local hc a parametric multi-segmented human manikin model with 48 body segments has been developed. Benchmark validations and regression models development are demonstrated through an example application, taken from the displacement ventilation structure. Finally, discussions and the applicability of the displacement ventilation subdomain models are detailed.