Combined simulation of airflow, radiation and moisture transport for heat release from human body.

As the thermal sensation of humans depends directly on heat transfer characteristics between the body surface and the surrounding environment, it is very important to clarify the heat transfer characteristics of a human body surface in detail. This paper describes a combined numerical (NOTE I) simulation system of airflow, thermal radiation and moisture transport based on a human thermo-physiological model used to examine the total (sensible + latent) heat transfer characteristics of a body surface. The human body is assumed to be naked (NOTE 2). Flow, temperature and moisture fields are investigated with 3-dimensional Computational Fluid Dynamics (CFO). The CFO uses a low-Reynolds-number type k- E turbulence model, with the generalized curvilinear coordinate system (Boundary Fitted Coordinates) to represent the complicated shape of a human body. Thermal radiation is calculated by means of Gebhart's absorption factor method, and the view factors are obtained by the Monte Carlo method. Gagge's two-node model is included to simulate the metabolic heat production and the thermoregulatory control processes of a human body. However, heat loss due to respiration is specified in advance and is not included in the simulation directly. The prediction results agree well with those of an actual human body in a similar situation.