Thermo-ventilation study by OpenFOAM of the airflow in a cavity with heated floor

An OpenFOAM (Open Field Operation and Manipulation) code is used to carry out a thermo- ventilation study of the airflow in a heated rectangular cavity. Three RANS (Reynolds Averaged Navier-Stokes) turbulence models (k-ε, RNG k-ε and k-ω SST) combined with four solvers treating the heat transfer phenomena are employed to test and validate the OpenFOAM code. The obtained results are in good agreement with the available measurements in the literature. They show that the choice of the turbulence model and the solver do not significantly affect the results. Based on the accuracy of results and execution time, the most satisfactory pair is obtained by the association of RNG k-ε model and BuoyantBoussinesqSimpleFoam (BBSF) solver. This pair is then used to perform a parametric study, in order to improve our understanding for ventilation control. To determine the best air ventilation configuration, an evaluation of the indoor air quality and the thermal comfort in the cavity is carried out. To this end, a new equation is implemented in an open-source C++ code OpenFOAM. It uses the concept of "air age" to quantify the air quality and two indexes, the "Effective Draft Temperature" and "People Dissatisfied", to quantify the thermal comfort. The results obtained show an evident contrast in the evolution in air quality and thermal comfort, therefore a compromise for the choice of air ventilation configuration is necessary, to have a both acceptable indoor air quality and thermal comfort.