Thermal Comfort Evaluation Using a Cfd Study and a Transient Thermal Model of the Human Body

Human thermal modulations are becoming a popular subject when concepts such as, safety and comfort are indispensables in workplaces design. The computational fluid dynamic software have been used and they have been assuming a greater impact in this field due to their higher accuracy. Also, CFD studies can provide detailed information about thermal comfort variables near a human computational manikin, which is difficult and expensive to obtain from experiments in laboratory. The present study is part of a wider project that combines thermal comfort modelling with the design of better and comfortable clothing. The dynamic heat and moisture transfer through the human–clothing–environment system and its effect on the transient physiological response is important and very complex involving several physical phenomena, such as, conduction, convection and radiation for heat transfer and diffusion, desorption, condensation and evaporation for moisture transfer. A CFD study of a room and a thermal manikin, have been developed in the Fluent code from Ansys. The influence of the supply opening conditions, namely air temperature, velocity and humidity has been investigated. A thermal computational manikin with real dimensions divided in 15 different parts has been simulated. Two situations have been compared: a constant temperature and a different temperature in each part. The simulated results have been compared against experimental results from the literature and it was concluded that the computational manikin, divided into different parts with different temperatures seems important to give accurate fluid flow and moisture distributions. In this paper, a new transient human thermal model, which combines a thermoregulatory model and one that describes the dynamic heat and moisture transfer through clothing, is presented. The human body-clothing-environment model developed will provide the transient boundary condition of the computational manikin allowing an accurate prediction of the indoor flow simulation. Senhorinha Teixeira, Celina P. Leão, Manuela Neves, Pedro Arezes, Ana Cunha, José Carlos Teixeira 2