Numerical simulations of the air flow generated by forced ventilation in a rectangular room

In these two years, due to the spreading of SARS-COV2 pandemics, it has become important to understand the dynamics of ventilation inside closed environments to determine the infection risk. It is known that Covid-19 is a viral infection and the probability to get infected by the virus increases inside closed spaces because saliva droplets, which contain the virus copies that cause the infection, could remain suspended in the air for long times. In this context, it is important to study the quality of the air inside indoor spaces and quantify the efficiency of ventilation systems in cleaning the air inside the environment. The study of the recirculation of the air becomes crucial to evaluate how long it takes to change a certain volume of air. During ventilation, some vortex could form inside a room, caused by the geometry, the ventilation type and temperature. This can affect the air change rate due to the formation of some recirculations. The problem of air ventilation inside a closed environment is numerically addressed in this thesis by solving the 3D Reynolds Average Navier-Stokes (RANS) equations on a rectangular domain. The air conditioning system is represented by setting two rectangular inflows that inject clean air inside the environment. The air exits from an additional couple of rectangular outflows at the opposite side of the room. Two cases are considered: heating and cooling. It is found that a perfect mixing model can adequately represent the air changing rate inside the room, especially in the case of cooling