Comparison of turbulent flow models in office medium and numerical simulation of various heating systems by using thermal comfort indices and Gagge model

In this study thermal comfort was investigated by the Computational Fluid Dynamics method in two and three-dimensional room geometry, and in case of underfloor heating, radiator heating and heating with air conditioner. One of the office rooms of Bursa Uludag University Mechanical Engineering Building was used for the geometry. A thermal manikin is modeled in the sitting position in the room. In order to test the accuracy of the methods used in the numerical study, some benchmarks studies which contain experimental data, were performed. k-ε models (Standard, Re-Normalisation Group, Realizable), k-ω models (Standard, shear stress transport, baseline) and BGS models which previously performed to benchmark studies in the literature, were compared with each other. Natural, forced and combined convection were tested separately. As a result of the studies, Standard k-ε turbulence model was chosen to be used in the thesis study because of its compatibility with experimental data. The flow in the room is time-dependent, compressible (ideal gas), mixed turbulent and the conservation equations are solved using ANSYS Fluent 18.0 software. To obtain the manikinsurface temperature, the manikinsurface is divided into sixteen different parts. The model skin temperature was calculated dynamically for each time step with the help of the code in C programming language developed based on Gagge thermal sensitivity model. Manikinsurface temperature is sensitive to ambient air temperature and speed. Temperature, velocity, PMV, PPD and PD distributions were obtained for each heating system. In the case of heating with air conditioner, different solutions have been obtained in nine different inlet boundary conditions. The effect of air conditioning blowing speed and temperature changes on air temperature in the room and comfort indices were investigated.