The optimization of thermal comfort in buildings and passenger cabins has become one of the major aspects during the conception phase of HVAC systems. The static PMV model is among the most recognized thermal comfort models and depends besides the dry air temperature, radiant temperature, humidity and air velocity also on the activity level and the clothing of the human. The aim of this investigation is the application of a simple and reliable model of human metabolism based on Olesen combined with CFD simulations to attain a sufficiently accurate reflection of the human heat exchange to evaluate the PMV index and predict thermal comfort in a fast and cost-effective way by CFD simulations. Basis of the CFD model developed in the current investigations are measurement results obtained during experimental investigations inside a cabin mock-up model placed in a controlled climatic chamber under various pre-defined steady-state environmental conditions. The cabin mock-up model is equipped with a radial-flow fan for influencing convective flow inside the cabin and a temperature control system for adjusting the ceiling surface temperature to obtain mainly the impact of radiant temperature on the thermal comfort. Depending on the activity level, the local clothing and ambient conditions such as the flow structure inside the cabin, the local human heat flux due to convection and radiation is examined within a steady-state, two-way-coupled CFD simulation coupling human and environment with one continuous fluid phase (dry air) and the usage of the discrete transfer radiation model.
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